Honesty is never a virtue on the Taiwan Strait

On 7 November 2025, Japanese Prime Minister Sanae Takaichi publicly linked a hypothetical Taiwan contingency to Japan’s domestic legal logic for a “survival-threatening situation” — language Japanese leaders have long handled with studied caution. Beijing treated the phrasing as more than a rhetorical slip and demanded retraction and clarification. On 16 December, Takaichi expressed “reflection” yet still did not withdraw the remark. If this sounds like a story about etiquette or gaffes, it is not. It is a stress test of strategic ambiguity — and the test is beginning to fail.

Strategic ambiguity is not a diplomatic accident. It is engineered uncertainty, designed to deter, delay and manage risk when clarity would lock states and leaders into escalatory promises. In the Taiwan context, ambiguity has historically functioned like a multi-layered stabiliser: Washington’s “one China” policy architecture — guided by the Taiwan Relations Act, the three US-PRC Joint Communiques and the Six Assurances — kept deterrence credible without making escalation automatic. Cross-strait formulas, too, used constructive vagueness to keep contact possible despite irreconcilable sovereignty claims.

But ambiguity is now squeezed from both ends: Tokyo’s Taiwan remark is inching toward conditional clarity, while Taiwan’s domestic politics increasingly pushes sharper, less deniable positioning. Once the ambiguity membrane is punctured, “re-ambiguation” is harder than it sounds — unless Washington and Beijing rebuild guardrails in writing.

To see why, we have to be clear about what strategic ambiguity is — and what it is not. It is not indecision. It is not bureaucratic confusion. It is a deliberate choice to leave key thresholds uncertain: what precisely triggers action, what form action would take, and how far it would go. The logic overlaps with classic deterrence theory: sometimes the most coercive signal is the one that leaves a rival unable to calculate risk precisely. Alongside it sits “constructive ambiguity”, the negotiation language intentionally capable of multiple interpretations, allowing agreement without resolving contradictions. Both are tools of control, not evidence of drift.

Ambiguity does several strategic jobs at once. First, it enables dual deterrence: discouraging an adversary from aggression while discouraging a partner from unilateral provocation. Second, it helps alliance management: coalitions rarely share identical risk tolerances, and ambiguity can hold them together by postponing a forced yes-or-no. Third, it provides crisis elasticity: leaders need off-ramps, and ambiguity gives them political room to de-escalate without looking like they capitulated. Finally, it plays to domestic politics: it lets governments signal resolve while avoiding commitments they cannot sustain. The trade-off is real — less clarity today in exchange for less catastrophe tomorrow.

Taiwan’s modern ambiguity is often described as a post-1979 design, but its practice is older. In June 1950, amid the Korean War, President Harry Truman ordered the US Seventh Fleet to prevent attacks on Taiwan and asserted that the island’s “final status” should await a broader peace settlement or international consideration — an early, explicit form of “status-undetermined” signalling that brought flexibility.

Taiwan’s legal-textual ambiguity was reinforced by postwar treaty language: Japan officially renounced Taiwan in the 1951 San Francisco Peace Treaty without specifying a recipient. Meanwhile, US security commitments were engineered for elasticity: early Cold War arrangements sought to deter attacks on Taiwan proper while avoiding an open-ended guarantee for every offshore contingency. These were not semantic games. They were crisis management tactics.

The contemporary US framework institutionalised those tactics. The 1972 US-China Shanghai Communique famously states that the US “acknowledges” that all Chinese on either side of the Taiwan Strait maintain there is one China and that Taiwan is part of China — wording that is intentionally not the same as recognising sovereignty. In 1979, Washington normalised relations with Beijing and then passed the Taiwan Relations Act, promising defensive support and maintaining the capacity to resist coercion, while still avoiding an automatic-war trigger. The 1982 communique, centred on arms sales, functioned as a recurring-friction guardrail: it did not settle Taiwan’s status, but it sought to manage the most dangerous loop in US-China relations. The point of this architecture was never maximal clarity. It was sustainable deterrence — strong enough to raise the price of force, flexible enough to prevent a slogan from becoming a fuse.

Ambiguity also existed inside the Taiwan Strait as a coexistence device. The 1992 Consensus exemplified constructive ambiguity: it enabled practical engagement by avoiding a single written definition of what “one China” meant, leaving room for “oral” and separate interpretations. That vagueness was meant to be functional. It served as an interface standard — allowing talks and exchanges to proceed when the alternative was paralysis. When such interface standards collapse, politics does not become “more honest”. It becomes more brittle.

Japan long maintained its own layer of useful vagueness on Taiwan: high strategic interest, low declaratory specificity. That was not passivity; it was prudence. It allowed Tokyo to strengthen deterrence and readiness — often in close coordination with the US — while avoiding language that could be portrayed as a decisive policy shift or a pre-commitment to intervene.

Takaichi’s 7 November remark matters because it nudged Japan’s declaratory policy toward conditional clarity: it suggested, in public and in legal terms, that Taiwan could map onto Japan’s most serious security category. The subsequent “reflection without retraction” on 16 December underscores the political reality: once words create a precedent, they become reference points for future crises, parliamentary arguments, alliance expectations and rival propaganda.

Does ambiguity inevitably mature into clarity? Not necessarily. Strategic ambiguity can be a stable equilibrium for decades when the major players share two preferences: avoiding a test and reinforcing the formula through repeated practice. For the Taiwan issue, policy pages, communiques and legislations traditionally reiterated a pattern that keeps deterrence credible while preserving room to manoeuvre. But ambiguity is fragile when actors gain incentives to force yes/no commitments — through domestic politics, coercive diplomacy or alliance reassurance demands.

Once punctured, re-ambiguition is possible but costly. Public clarity creates public stakes; attempts to walk it back invite charges of weakness at home and unreliability abroad. What typically emerges is not a return to “original ambiguity”, but a new hybrid: outward ambiguity paired with inward operational clarity.

Taipei’s internal trajectory intensifies this pressure. The Lai Ching-te administration’s discourse is now widely seen as trending toward sharper differentiation — what critics describe as a “new two-state” theory — and it has used tougher labels such as calling mainland China an “external hostile force”. Reports of Taiwan’s Straits Exchange Foundation chair Wu Fengshan’s resignation amid discomfort with shrinking rhetorical space for a broader “Chinese nation” framing, whatever the precise proximate cause, captures the larger dynamic: the domestic room for constructive ambiguity is narrowing. Beijing, meanwhile, seeks to compel clarity from outside — pressuring Japan’s language and testing US boundaries. The result is a dangerous mismatch: local political clarity accelerates just as great powers still depend on ambiguity for crisis management.

That is why Washington and Beijing should consider rebuilding written guardrails — potentially through a fourth Joint Communique that explicitly restates the Taiwan issue as a shared stability agenda rather than a rhetorical battleground. This would not be a grand bargain. It would be a repair tool. The precedent is there: the communiques functioned as crisis management tactics, and the 1982 Communique targeted the most combustible recurring friction point. A fourth communique could put the US’s longstanding political statement on the State Department’s website, US non-support for Taiwan independence, into written format. The goal would be to reduce misperception, restore a ceiling of disciplined ambiguity, and prevent allies’ declaratory drift — Tokyo included — from becoming the tail that wags the strategic dog.

A final accelerant makes this repair work more urgent: nuclear anxiety. Reports that Japan has had internal “trial balloons” about considering nuclear weapons — followed by reaffirmations of its non-nuclear stance — signal stress in extended deterrence and crisis expectations. Even if such ideas remain politically and legally remote, their very circulation raises the stakes for everyone. The US, China and Russia all have an interest in preventing nuclear proliferation cascades in Northeast Asia, and that interest should translate into stronger crisis guardrails — not looser talk and thinner ambiguity.

Strategic ambiguity is not weakness; it is disciplined restraint. But it only works when leaders treat it like a safety system, not a rhetorical playground. Japan’s recent Taiwan phrasing shows how easily ambiguity can be punctured—and how quickly others will weaponise the puncture. If the shared goal remains deterrence without disaster, Washington and Beijing should do the unglamorous work again: write down the guardrails, repeat them, and make ambiguity credible.

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