US Arms Sales to Taiwan Explained: How They Work and Why China Calls Them a Red Line

As the Trump administration navigates the final stages of an Iran deal and courts Beijing’s cooperation on a range of issues from the Strait of Hormuz to trade, a separate but equally consequential flashpoint has quietly escalated: Washington has paused a $14 billion arms package to Taiwan following President Trump’s state visit to China, where Xi Jinping made unmistakably clear that Taiwan is a “red line that must not be crossed.”

The pause has triggered alarm in Taipei, concern in Congress, and a fresh round of diplomatic maneuvering in Beijing. To understand what is at stake, it helps to understand how US arms sales to Taiwan actually work and why China treats each one as a provocation of the highest order.

The Legal Foundation: Taiwan Relations Act

The entire architecture of US arms sales to Taiwan rests on a 47-year-old piece of legislation. The Taiwan Relations Act, signed into law on April 10, 1979, was the legal mechanism Washington created to manage its relationship with Taipei after formally recognizing the People’s Republic of China and severing official diplomatic ties with Taiwan.

The TRA’s core security provision is explicit: the United States shall provide Taiwan with “such defense articles and defense services in such quantity as may be necessary to enable Taiwan to maintain a sufficient self-defense capability.” It further states that any non-peaceful effort to determine Taiwan’s future would be a matter of “grave concern” to the United States.

Crucially, the TRA does not require congressional approval for individual arms sales it places primary authority with the executive branch. Under the Arms Export Control Act framework, the President notifies Congress of proposed sales, and Congress has 30 days to pass a resolution of disapproval if it objects. In practice, resolutions of disapproval are rare. The Reagan-era “Six Assurances” added a further commitment that Washington would not consult Beijing before approving sales a pledge that subsequent administrations have nominally maintained.

The Scale of the Backlog

The volume of arms the United States has committed to sell Taiwan is staggering. In December 2025, the Trump administration notified Congress of over $11 billion in new Foreign Military Sales cases the largest single package by dollar value in history. That brought the total backlog of approved but not yet delivered arms to approximately $32 billion.

CNN reported that among 23 major US arms sales to Taiwan over the past decade, five have been fully delivered, three partially delivered, and fifteen remain in production. The delays reflect both the complexity of defense procurement and the diplomatic sensitivity of rushing delivery.

Recent packages have included HIMARS rocket artillery launchers, 291 ALTIUS-600M loitering munitions, and 108 Abrams tanks the final units of which were delivered in April 2026. Radio Free Asia reported that Taiwan has been pushing for faster delivery timelines on all outstanding orders, particularly as China’s military modernization accelerates.

Why China Calls It a Red Line

Beijing’s position on US arms sales to Taiwan is consistent, comprehensive, and non-negotiable at least rhetorically. China’s Foreign Ministry has stated that its “firm opposition to US arms sales to China’s Taiwan region is consistent, clear and unwavering,” calling on Washington to “stop arms sales to Taiwan and take concrete actions to maintain peace and stability in the Taiwan Strait.”

Xi Jinping’s framing goes further. Taiwan sits at “the core of China’s core interests” language that in Chinese diplomatic usage signals maximum sensitivity. Newsweek reported that Chinese state media has explicitly framed US arms sales as a military red line, warning of potential responses beyond diplomatic protest.

The reason is strategic, not merely symbolic. Each weapons system the US delivers to Taiwan increases the cost in time, casualties, and equipment of any Chinese military operation against the island. HIMARS can strike targets at range. Loitering munitions are difficult to intercept at scale. Abrams tanks raise the cost of any amphibious assault. From Beijing’s perspective, every arms sale is a direct intervention in what China considers an internal matter of national unification.

Trump’s Pause and What It Signals

The decision to pause the $14 billion arms package following Trump’s Beijing visit is the most significant deviation from standard US arms sale practice in years. The Washington Post reported that the pause appears to reflect deliberate accommodation of Chinese diplomatic pressure with Beijing reportedly also holding up a planned visit by US Undersecretary of Defense Elbridge Colby over the arms deal.

Foreign Policy reported that Taiwanese officials and US lawmakers have expressed concern that Trump’s Taiwan commitment is softening as his administration simultaneously pursues a China trade framework, manages the Iran crisis with Chinese diplomatic support, and seeks broader great-power accommodation with Beijing.

South China Morning Post analysis described the pause as evidence that Beijing has successfully “arrested the trend” on Taiwan arms sales at least temporarily through sustained diplomatic pressure on the Trump White House.

Whether the pause becomes a cancellation, a renegotiation, or a delayed resumption will tell us more about the durability of US commitments to Taiwan than any official statement could. The Taiwan Relations Act remains law. What has shifted is the political will to enforce it at maximum pace and that shift, however temporary, is precisely what Beijing was seeking.