6.6 Treaty Succession

What happens to the thousands of treaties currently applying to Scotland as part of the UK?

Under the principles of the Vienna Convention on Succession of States in respect of Treaties and related customary international law, not all UK treaties automatically bind a newly independent Scotland, nor does it automatically succeed to them. Scotland would review the treaty stock and notify succession to those multilateral treaties it wishes to continue, while negotiating new or revised bilateral agreements where necessary. Critical treaties — including those on human rights, aviation, climate, extradition and other essential functions — would be prioritised for early continuity or succession. A systematic review and notification process would be established as part of the transition.

Treaties are the legal wiring of a modern state. They cover air services, human rights, extradition, climate obligations, maritime safety, consular relations and thousands of technical arrangements that keep daily life and international cooperation functioning. Scotland currently benefits from and is bound by these instruments only as part of the United Kingdom. Independence ends that automatic coverage. The legal starting point is neither full inheritance nor total rupture; it is an active process of review, choice and notification.

The main design choice is deliberate succession: continuity where it matters for rights, safety and essential cooperation; independent choice where Scottish interests diverge from the inherited UK position. The main constraints are the sheer volume of treaties, the need for counterpart agreement on bilateral instruments, administrative capacity to run a systematic review, and the risk of legal gaps if prioritisation fails. Continuity for critical regimes is a design requirement, not a slogan. Automatic inheritance is not claimed because international law does not provide it.

This section sets out how that process would work. Under the principles of the Vienna Convention on Succession of States in respect of Treaties and related customary international law, a newly independent Scotland is not automatically bound by all UK treaties and does not automatically succeed to them. Scotland would review the treaty stock, notify succession to the multilateral treaties it wishes to continue, and negotiate new or revised bilateral agreements where necessary. Critical treaties — human rights, aviation, climate, extradition and other essential functions — would be prioritised for early continuity or succession. A systematic review and notification process would be established as part of the transition machinery. Continuity where it matters for rights, safety and essential cooperation is a design requirement. Independent choice where Scottish interests diverge from the inherited UK position is preserved. Scotland does not claim automatic inheritance because international law does not provide it. Claiming otherwise would mislead the public and partners about legal reality.

Current Position and Legal/Institutional Baseline

The United Kingdom’s treaty network currently covers Scotland. Multilateral and bilateral treaties to which the UK is a party apply to Scotland as part of the UK. There is no separate Scottish treaty inventory, no separate Scottish notifications to depositaries and no separate Scottish bilateral treaty practice. Human-rights instruments, aviation and maritime conventions, climate agreements, extradition and mutual legal assistance treaties, and a very large number of technical arrangements all apply through the UK’s status as party.

Independence would change the legal baseline. Scotland would become a distinct subject of international law. A combination of treaty law, customary international law and practical negotiation governs the fate of the predecessor state’s treaties. The Vienna Convention on Succession of States in respect of Treaties (1978) sets out principles that, even where not formally binding on every state, provide the main reference framework used in practice. In broad terms, a newly independent state is not simply bound by all the treaties of the predecessor state, nor does it automatically inherit them without action of its own. Two practical consequences follow. First, Scotland would not be automatically obliged to continue every UK treaty that currently applies to its territory. Second, Scotland would not automatically receive the benefit of those treaties without taking steps to succeed to them or to negotiate replacements. Treaty succession is therefore an active process, not a passive inheritance.

International practice confirms the position. Newly independent states have used notification of succession to maintain continuity with important multilateral regimes while avoiding abrupt legal vacuums. Bilateral treaties require the other party's agreement. Trade agreements, already addressed in the WTO and trade-agreement succession section, follow the same logic: they do not roll over automatically. The institutional task is to convert the inherited stock into a managed Scottish treaty position through inventory, prioritisation, notification and negotiation.

Mechanism and Delivery

The mechanism is a systematic review and notification process established as part of the transition machinery. The process would include compilation of the treaty stock that currently applies to Scotland; classification by type (multilateral or bilateral) and by priority; legal and policy assessment of the implications of succession, non-succession or renegotiation; a programme of notifications to depositaries and counterparties; and tracking of responses and negotiation of any necessary replacements or transitional measures. This work would require dedicated capacity within the foreign ministry and legal services, supported by specialist advice where needed. It would begin during the transition period so that the most critical continuities are in place by Independence Day or shortly thereafter.

For multilateral treaties — those open to many parties, such as major human-rights conventions, environmental agreements, aviation and maritime conventions, and many technical instruments — the usual path is notification of succession. Scotland would examine the stock and decide, treaty by treaty, whether to notify succession, thereby becoming a party in its own right on the existing terms; decline to succeed, accepting that the treaty would no longer apply; or accede later under the treaty’s ordinary accession procedures if a different timing or terms are preferred. Depositaries receive the notification and circulate it. The process is formal and trackable. It is also capacity-intensive when the stock runs to thousands of instruments: each decision requires legal assessment of obligations, reservations and practical implications. Selective succession is consistent with sovereignty. The constraint is that non-succession can create gaps that must be weighed against any desire to exit a particular regime.

For bilateral treaties, continuity depends on the other party's agreement. Scotland would need to seek the other state's agreement to treat Scotland as a successor party; negotiate a new bilateral treaty reflecting current interests; or accept that the treaty lapses in relation to Scotland and manage the consequences. Given the number of bilateral treaties, prioritisation is essential. Treaties that underpin critical functions — extradition, air services, mutual legal assistance, investment protection and similar — would be addressed first. Lower-priority cultural or technical arrangements can wait. The dependency on counterpart goodwill is real: a partner state can decline succession or demand revised terms. That is a structural feature of bilateral succession, not a failure of Scottish planning.

Prioritisation of critical treaties is the operational response to volume. A systematic review would identify priority categories for early action, including human rights and international humanitarian law, to maintain continuity of existing protections already embedded in Scots law and the interim constitutional design; aviation and maritime, to keep air services, safety regulation and shipping arrangements functioning; climate and environment, to maintain participation in core multilateral environmental regimes; extradition, mutual legal assistance and security cooperation, to avoid gaps in law enforcement and justice cooperation; trade-related and economic treaties not already covered by the WTO and trade-agreement processes; and consular and diplomatic instruments relevant to the new diplomatic network. High-priority treaties would be targeted for succession notifications or interim continuity arrangements as early as possible in the transition. Lower-priority instruments would follow on a published schedule. Without prioritisation, the volume of work would overwhelm capacity and produce exactly the legal voids the process is meant to prevent.

Public and partner communication forms part of delivery. Depositaries, airlines, courts and counterpart justice ministries need to know which regimes remain in force for Scotland. Silence creates operational risk even when the legal intention is continuity. Clear internal guidance for Scottish courts and agencies on which treaties apply from Independence Day, and a published programme to make the process auditable, complete the mechanism.

Continuity Design

Continuity for critical regimes is a design requirement. Early notification for priority multilateral instruments, interim arrangements or provisional application where bilateral partners agree, clear internal guidance for Scottish courts and agencies, and a published programme are the instruments of that continuity. Individuals, businesses and partner states should not face sudden legal voids in areas such as human rights, aviation safety or extradition. At the same time, Scotland should not be locked indefinitely into every commitment the UK undertakes. The review-and-notification process strikes that balance.

Human-rights continuity links to the interim constitution and the human-rights framework already set out. Domestic incorporation provides a backstop for rights protection while succession is completed; international treaty continuity remains valuable for monitoring, individual petition where applicable, and external accountability. Aviation and maritime continuity protects safety regulation and commercial operations. Extradition and mutual legal assistance continuity protects law-enforcement cooperation. Climate continuity maintains participation in core multilateral regimes under full Scottish control of targets and implementation. Consular and diplomatic instruments support the new diplomatic network. In each priority category, the design seeks continuity by action — notification, interim arrangement, guidance — rather than by assumption.

Constraints and Trade-offs

Legal constraints

Not all UK treaties automatically bind Scotland and do not automatically succeed to them. Notification of succession for multilateral instruments is the formal path to continuity on existing terms; without it, application ends. Bilateral succession requires counterpart consent. Provisional or interim measures must remain within international law. Domestic guidance to courts and agencies must accurately reflect which obligations bind from Independence Day. Legal design must avoid claims of automatic inheritance that cannot be sustained and must provide auditable processes for notification and tracking.

Fiscal constraints

Staff time, specialist legal advice, travel for bilateral talks and systems for tracking notifications are public costs inside the external affairs and justice budgets. They are modest relative to defence or social security, but they compete for scarce skilled lawyers. Under-funding produces backlog and gaps. Costs sit inside the fiscal framework and should be line items in transition planning. Prioritisation manages the burden by concentrating early effort on critical regimes rather than attempting to treat the entire stock simultaneously.

Operational constraints

The volume of treaties is very large. An ad-hoc approach would be unmanageable. Dedicated capacity, an early start during the transition, a classified inventory and a notification timetable are conditions of success. Bilateral succession depends on counterpart responsiveness; delays or refusals create gaps that must be managed. Internal coordination across foreign ministry, legal services, transport, justice and environment portfolios is required so that priority assessments are coherent. Public and partner communication must keep pace with notifications so operators and courts are not left uncertain.

Political constraints

Claims that “all the treaties carry over” are attractive in political rhetoric and incorrect in law. This framework rejects them. Sustaining confidence requires honesty about the active character of succession, combined with visible prioritisation of critical regimes and measurable continuity in those regimes. Counterpart states will negotiate bilateral succession according to their own interests. Domestic political management must support the dedicated capacity and the early start that make continuity real, rather than treating succession as a residual legal task.

Time constraints

The review must begin during the transition if the most critical continuities are to be in place by Independence Day or shortly thereafter. Priority notifications should be advanced early. Bilateral talks on critical instruments — extradition, air services, mutual legal assistance — require time and counterpart engagement. Lower-priority instruments follow on a published schedule. Delay maximises gap risk. Early systematic work is the superior design.

Consistency with the Wider Framework

Treaty succession sits alongside WTO accession, the negotiation of new trade agreements, membership of international organisations and the building of a diplomatic network. Together these processes convert Scotland from a territory to which UK treaties apply into a state that is a party to treaties in its own right. The approach is orderly, prioritised and focused on maintaining essential legal continuity while asserting independent choice over the longer term.

It aligns with the human-rights framework: continuity of core instruments through interim and permanent constitution plus succession where chosen. It aligns with borders and security cooperation through extradition and mutual legal assistance. It aligns with aviation and transport continuity, with climate policy under full Scottish control of targets and international participation, and with the diplomatic service’s early workload of notifications and bilateral talks. It does not depend on EU membership. It does not alter sterlingisation, NATO membership or the nuclear basing agreement, though status-of-forces and related instruments would form part of the priority bilateral and multilateral review. Fiscal rules and institutional capacity constraints apply: succession work is necessary state-function spending, not optional diplomacy.

Hardest Critiques and Direct Responses

Feasibility

A systematic succession programme is feasible for a state that plans it as a core transition workstream. Other newly independent states have done it. It is not feasible as an informal side-task for a small legal team already overloaded with constitutional and negotiation work. Dedicated capacity and an early start during the transition period are conditions of success. Prioritisation makes volume manageable. Feasibility falls only if the work is left unresourced, started late, or replaced by claims of automatic inheritance.

Cost and fiscal burden

Staff time, specialist advice and tracking systems are real costs and must be budgeted. They are modest relative to major spending programmes but compete for scarce legal capacity. Under-funding produces backlogs and gaps—a false economy that creates operational and legal risk. The framework treats succession capacity as a necessary line-item in transition planning. Prioritisation concentrates early expenditure on critical regimes where gaps would be most damaging.

Dependence on agreement

Dependence is moderate for multilateral succession: notification is largely unilateral once Scotland is a state, though depositary practice and counterpart reactions matter. Dependence is high for bilateral succession and for practical UK cooperation in supplying a complete treaty inventory and historical records. If the UK is slow to share documentation or if bilateral partners refuse succession, Scotland faces gaps or renegotiation. Contingency prioritises the most critical instruments and, where necessary, provisional domestic measures that preserve functional outcomes within the limits of international law while formal succession is pending.

Transition risk

Unnotified multilateral treaties that counterparties or courts treat as inapplicable, lapsed bilateral extradition or air-service arrangements, and uncertainty inside Scottish institutions about which obligations still bind are material risks. Mitigation includes a systematic inventory, priority notifications before or on Independence Day, interim bilateral side-letters where partners agree, and clear guidance to courts, regulators, and operators. Domestic incorporation supports human-rights continuity as a backstop while international succession completes. Residual gaps in lower-priority instruments are accepted as the price of prioritisation; gaps in critical regimes are the failure mode the design is built to prevent.

Alternatives (status quo and previous proposals)

Automatic inheritance of all UK treaties is not available under the applicable law and practice; asserting it would be false and is rejected. Complete rupture — succeeding to nothing — would create dangerous voids in aviation, rights and law enforcement and is rejected. Waiting until after Independence Day to begin the review maximises gap risk; early systematic work during transition is the superior design. Relying on EU membership to “cover” treaty continuity is incompatible with the decision not to seek EU membership and would not cover the bilateral stock in any event. The design chooses deliberate succession through inventory, prioritisation, notification and negotiation, with critical regimes first.

Political and public credibility

The claim most likely to be called unrealistic is that Scotland can manage thousands of treaties without chaos, or that critical regimes will “just continue.” The precise answer is that volume is managed by prioritisation and a dedicated process, not by reading every instrument on day one; and that critical regimes continue only if succession is notified or interim arrangements are secured — which is why those steps are built into transition design rather than assumed. Credibility is a published inventory classification, a notification schedule and measurable continuity in priority sectors — aviation, extradition, core human-rights instruments — not reassurance without machinery. Readers who prefer the language of automatic carry-over are invited to evaluate the framework on the legal facts and on the continuity tools actually available.

Position Summarised

All UK treaties do not automatically bind a newly independent Scotland and do not automatically succeed to it. It would review the treaty stock, notify succession to the multilateral treaties it wishes to continue, and negotiate new or revised bilateral agreements where necessary. Critical treaties on human rights, aviation, climate, extradition and other essential functions would be prioritised for early continuity or succession.

A systematic review and notification process would be established as part of the transition. The aim is continuity where it matters and independent choice where it counts. Treaty succession is managed deliberately, not left to automatic inheritance or abrupt lapse. Capacity, prioritisation and early action during the transition period are the conditions that make continuity real. Public and partner communication, internal guidance to courts and agencies, and an auditable programme complete the design.

Conclusion

What happens to the thousands of treaties currently applying to Scotland as part of the UK? They neither vanish nor transfer by magic. Scotland would run a systematic review, succeed by notification to the multilateral instruments it chooses to keep, and negotiate bilateral continuity or replacements where partners agree — with human rights, aviation, climate, extradition and other critical regimes first.

That is slower and more technical than claiming “nothing changes,” and more responsible than risking legal voids. Continuity is designed through inventory, priority, notification and interim arrangements. Independent choice is preserved by the right not to succeed or to renegotiate. The limit of the claim is clear: success depends on starting the work during transition, funding the legal capacity, and securing partner cooperation on the bilateral stock. Those are achievable tasks in an orderly independence process. They are not automatic.

The final section of this international-relations part turns to international development and overseas aid policy — how Scotland would set its own programme, scale and priorities once it is a state among states.

This analysis forms part of People’s Future Scotland: The Independence Debate, a non-party framework examining the practical design of independence. Each section is written to withstand professional scrutiny and to prioritise mechanism, constraint and continuity over aspiration.