"Even long-standing free trade agreements do not preclude tariff wars between signatories." Critically analyse using the CUSMA/U.S.-Canada case.

Free trade agreements bind signatories to reciprocal tariff concessions, yet they rest on political consent, not enforceable sovereignty. The 2025-26 U.S.–Canada tariff escalation — between CUSMA partners and NATO/NORAD allies — shows that treaty text restrains, but does not eliminate, protectionist reversal.

Why FTAs fail to preclude tariff wars

• Security and emergency exceptions let states bypass concessions: Washington imposed 50% tariffs on select Canadian goods after talks collapsed in August 2026, and Ottawa retaliated "dollar for dollar" on roughly $20 billion of U.S. steel, dairy, agricultural equipment and pulp-and-paper from 8 September 2026 [1][2].
• Unresolved structural frictions survive the agreement. Softwood lumber and Canada's dairy supply management predate CUSMA; the WTO softwood disputes (DS236, DS247, DS257, DS264, DS277, DS311) closed only through a negotiated 2006 Softwood Lumber Agreement, not final adjudication [3].
• Domestic politics overrides treaty logic — PM Carney's "we got attacked" framing, and Ontario's threat to curb electricity and critical-mineral flows, show sub-national and electoral actors escalating beyond commercial calculus [1].
• Weak enforcement: slow, consent-dependent dispute settlement makes unilateral tariffs cheaper than litigation.

Why the FTA still matters

• CUSMA supplies a standing negotiating channel; Canada has repeatedly exempted or lifted duties on CUSMA-compliant goods, containing the war's scope [2].
• Deep integration itself deters: with about three-quarters of Canadian exports bound for the U.S., mutual supply-chain damage pushes both toward settlement [4].
• Historically such disputes end in managed agreements rather than permanent rupture [3].

An FTA is therefore a moderating framework, not an immunity clause — it narrows and channels conflict without removing the sovereign option to defect. The durable remedy lies in strengthening binding dispute settlement and closing legacy irritants like lumber and dairy at the negotiating table. For India, the lesson for its own FTA negotiations is clear: enforceable dispute mechanisms and diversified export markets matter as much as tariff schedules.