The U.S. and Taiwanese Militaries Can’t Really Fight Together
In Washington, much of the debate over Taiwan’s security has focused on the island’s defense budget and purchases of U.S. weapons. On the first, Taiwan is headed in the right direction since President Lai Ching-te pledged to spend 5 percent of GDP on defense by 2030. On the second, the Trump administration has announced that a record $14 billion package of arms sales to Taipei is now on hold as a “negotiating chip” with Beijing. But while it is possible that future U.S. arms deliveries will be delayed or bundled in smaller packages, arms sales will likely continue.
U.S. President Donald Trump has also been ambiguous about the United States’ willingness to come to Taiwan’s assistance if China invaded or blockaded it. Although this is consistent with a long-established U.S. policy of strategic ambiguity on the issue, Trump’s statements stand in contrast to his predecessor’s, Joe Biden, who said that he would intervene to defend Taiwan on multiple occasions—statements that were quietly walked back by a spokesperson each time.
In Washington, much of the debate over Taiwan’s security has focused on the island’s defense budget and purchases of U.S. weapons. On the first, Taiwan is headed in the right direction since President Lai Ching-te pledged to spend 5 percent of GDP on defense by 2030. On the second, the Trump administration has announced that a record $14 billion package of arms sales to Taipei is now on hold as a “negotiating chip” with Beijing. But while it is possible that future U.S. arms deliveries will be delayed or bundled in smaller packages, arms sales will likely continue.
U.S. President Donald Trump has also been ambiguous about the United States’ willingness to come to Taiwan’s assistance if China invaded or blockaded it. Although this is consistent with a long-established U.S. policy of strategic ambiguity on the issue, Trump’s statements stand in contrast to his predecessor’s, Joe Biden, who said that he would intervene to defend Taiwan on multiple occasions—statements that were quietly walked back by a spokesperson each time.
But the debate over budgets, arms sales, and strategic ambiguity has masked the most challenging issue that Taiwan and the United States would face during a potential joint defense of the island: the lack of interoperability between the two countries’ military forces. Addressing this is as urgent as any weapons sale on the books.
If Chinese forces attempted to cross the Taiwan Strait tomorrow and the United States came to Taiwan’s aid, the U.S. and Taiwanese militaries would struggle to fight together effectively. Their combined forces would experience gaps in how their systems communicate, how their commanders coordinate, and how their units operate alongside one another. These gaps will cost time and cause disruptions. In combat, this will cost American and Taiwanese lives and ultimately threaten the campaign itself.
The roots of this problem run to 1979, when the United States severed formal diplomatic and military relations with Taiwan as the price of normalization with the People’s Republic of China. Overnight, the institutional ligature of the pre-1979 U.S.-Taiwan alliance, including joint military exercises, combined staff planning, and shared doctrine, was all cut away.
In contrast, the U.S.-Japan and U.S.-South Korea alliances continued to develop through the last four decades, accumulating layer upon layer of operational integration. These include common communication architectures, interoperable command and control systems, combined exercise programs, shared intelligence frameworks, and thousands of officers who have trained alongside their counterparts and understand how the other force thinks and fights.
Taiwan got none of that. The relationship survived through arms sales and informal channels, but the operational integration that can transform two separate militaries into a combined fighting force ceased to exist. The result is a gap measured not in years but in generations of lost institutional knowledge.
The U.S. Congress recognized this problem when it passed the Taiwan Enhanced Resilience Act as part of the 2023 National Defense Authorization Act. This landmark legislation authorized expanded military training, increased exchange programs, and directed the Defense Department to address specific interoperability shortfalls. It was an important acknowledgment that the status quo was unsustainable. But authorization is not implementation, and the bureaucratic, diplomatic, and political frictions involved in actually rebuilding operational integration with Taiwan have slowed progress to a pace that does not match the urgency of the threat.
Interoperability begins with technology, and it means something specific and demanding.
At the strategic and operational level, it means that U.S. and Taiwanese command and control systems need to be compatible in their IT architecture and that commanders on both sides are looking at the same operational picture in real time. The United States and Taiwan are not at that point today. Getting there requires both sustained technical investment and the political will to treat Taiwan’s integration into U.S. military networks as a strategic priority.
At the tactical and operational level, it means that fused targeting data from Taiwanese sensors, such as radars, surveillance assets, and coastal defense networks, can all feed directly into U.S. sensor and shooter networks without manual translation, time delay, or lost fidelity. The same holds for U.S. sensor data flowing back into Taiwanese fire control networks. It means that a Taiwanese air defense battery and a U.S. Aegis destroyer operating in the same battlespace are integrated, which includes a shared common operating picture and coordinated engagement authorities. This tactical integration is an expensive but necessary investment.
But technological integration without process integration is like hardware without software. Interoperable processes means that U.S. and Taiwanese units are exercising together regularly enough to have worked through the friction in doctrines, command cultures, and decision tempos that emerges when conducting combined operations. We see the fruits of this effort in the U.S. military’s cooperation with Japan and South Korea, who both (usually separately) exercise with U.S. forces continuously. With Taiwan, the baseline exercise level remains low, constrained by Washington’s excessive diplomatic sensitivity to China and inadequate policy ambition.
An equally critical process is combined staff planning. U.S. and Taiwanese operational planners need to be working through Taiwan Strait scenarios together, developing shared understanding of terrain, threat, and decision points before any crisis begins. The Taiwanese military has detailed knowledge of the operational environment that no U.S. planner can replicate from a map. U.S. planners bring experience in complex joint operations that Taiwan cannot generate on its own. This is a powerful combination that could produce a credible defense plan.
Finally, at the foundation of every durable alliance relationship is a network of warfighters who know each other, trust each other, and understand how the other thinks. This can be achieved by two paths.
First, there is regular interaction between senior military officers, which the United States has with every possible military partner except Taiwan. For fear of provoking China, U.S. senior leader engagement with Taiwanese counterparts—both at the uniformed military and civilian levels—is heavily proscribed.
Another instrument is the International Military Education and Training (IMET) program, which the U.S. military has used to build networks with partners across the world for seven decades. Those who attend U.S. officer courses and war colleges return to their home militaries with a network of U.S. counterparts and a comprehensive understanding of how the U.S. military operates that no exercise can fully replicate.
Taiwan’s participation in IMET has been limited and inconsistent relative to what the relationship demands. Maximizing Taiwanese participation in IMET, especially in the U.S. Army’s captain’s courses (and their Navy and Air Force equivalents) should be viewed as a strategic investment, not an administrative detail. A Taiwanese officer who studied at Fort Sill or Newport and built relationships with their U.S. counterparts is worth more to combined operational effectiveness than almost any piece of hardware that Washington could sell to Taipei.
Effective deterrence requires Chinese President Xi Jinping to believe that the cost of an invasion exceeds any conceivable gain. An integrated, interoperable U.S.-Taiwanese military posture with combined command and control, fused targeting networks, practiced joint operations, and officers who know and trust each other is the ultimate deterrent. Moving forward on interoperability signals to China that strategic ambiguity has its limits—that the United States will act to protect its interests and defend its partners. A Taiwan that has the right weapons but cannot connect them to U.S. combat power in a coherent and combined arms campaign is an invitation to invasion.
Taiwan is spending the money. Delay or not, the United States will sell the weapons. The question now is whether Washington has the political will to close the interoperability gap before it becomes the gap through which a war begins.
Mark Montgomery is the senior director of the Center on Cyber and Technology Innovation at the Foundation for Defense of Democracies and a former rear admiral in the U.S. Navy.
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The pause of a $14 billion arms package raises concerns about U.S. support for Taipei.