In the days following the Israeli-U.S. strikes on Iran, both chambers of the U.S. Congress – the Senate and the House of Representatives – voted on a War Powers Resolution aimed at halting U.S. President Donald Trump’s military action, which was not given congressional authorization. Although the measure failed in both chambers – with nearly all Republicans voting against it and publicly supporting the administration – a closer look suggests that Republican support for the war may not be as solid as it appears. An increasing number of Republican lawmakers are privately expressing concern. 

As Trump prepares for an upcoming meeting with Chinese President Xi Jinping, where Taiwan will almost certainly be discussed, these underlying Republican attitudes toward U.S. military involvement abroad could shape Trump’s negotiating position. 

The War Powers Resolution was intended to block further U.S. military action in Iran without congressional approval under the 1973 War Powers Act. Had it passed both chambers, it would have represented a major challenge to Trump’s expansive view of presidential authority in foreign affairs. Republicans largely voted along party lines; Senator Rand Paul (R-KY), a co-sponsor of the resolution, was the only Republican in the Senate to support it. As a prominent voice of the New Right in American politics, Paul has long advocated for greater restraint in U.S. foreign policy.

While Paul appeared to be the lone dissenter, his concerns are quietly shared by others in the Republican caucus. Some Republican senators, despite voting against the resolution, have publicly voiced concerns about the administration’s strategy. Senator Susan Collins (R-ME) warned that the Trump administration must keep lawmakers fully briefed on developments, while Senator Lisa Murkowski (R-AK) said she is troubled by the lack of a clear endgame for the conflict.

Similarly, in the House, only two Republicans – Representatives Thomas Massie (R-KY) and Warren Davidson (R-OH) – supported the resolution. However, other Republicans reportedly harbor similar concerns but have largely chosen to express them privately.

Support for military action often swells in the early days of a conflict but tends to fade over time. The Iraq War offers a telling example: a large majority of Americans supported the invasion in its early stages, but support fell dramatically as the conflict continued. A similar dynamic may already be emerging among Republicans, many of whom remain weary after the “forever wars” in Iraq and Afghanistan. 

Trump himself acknowledged that the conflict with Iran could last weeks, which has raised concerns within the party that the United States could again be drawn into a prolonged Middle Eastern war. Representative Tim Burchett (R-TN), for instance, warned that “MAGA voters” should worry that military action in Iran might become “another forever war.” 

These concerns are also reflected in how Republican lawmakers describe the conflict. Increasingly, some have avoided calling it a “war” altogether. House Speaker Mike Johnson (R-LA) has referred to the military campaign as an “operation,” while Senator Josh Hawley (R-MO) argued that a war only exists when “ground troops” are deployed. Such rhetorical maneuvering highlights the political sensitivity surrounding a potentially unpopular military engagement, especially for a party that has increasingly criticized prolonged foreign interventions. 

Public opinion reinforces these concerns as polling suggests that a majority of Americans disapprove of the strikes on Iran. Hence, Trump appears to have unified Republican support on the surface, but a closer examination reveals a more complicated reality: Many Republican lawmakers may be backing the administration not because they fully support the rationale for the war, but because the conflict has already begun. In their view, passing a resolution now could send the wrong message to Iran or undermine U.S. troops already involved.

In other words, these lawmakers may believe that the United States has already crossed the Rubicon. If the conflict has begun, they argue, the country must see it through to a satisfactory outcome. Yet had Congress been given the opportunity to vote on the initiation of the war beforehand, many Republicans might well have opposed it.

These nuanced Republican attitudes could influence not only the trajectory of the Iran conflict, but also Trump’s upcoming meeting with Xi Jinping. Trump may prefer to focus discussions with Xi primarily on economic issues, particularly as he seeks a tangible economic achievement he can present to Republican voters ahead of the upcoming midterm elections. China, however, may view the meeting differently. From Beijing’s perspective, the current moment offers an opportunity to “look for cues” on how Trump might respond to other geopolitical flashpoints – most notably Taiwan. After all, this is the second time in recent months that the United States has used military force against a country with close ties to China, potentially giving Beijing reason to probe Washington’s resolve.

What could embolden China in such discussions is precisely the unease among Republicans about the duration of the Iran conflict. Given China’s military capabilities and geographic proximity to Taiwan, any conflict over the island could easily become a prolonged war of attrition. That possibility represents the ultimate concern for many Republicans who remain wary of long-term military entanglements. 

If Republican support for the Iran war begins to erode – as history suggests it might – China may draw an important lesson: even a president with imperial tendencies like Trump may struggle to sustain domestic political support for a prolonged conflict. Should Beijing credibly signal that any military confrontation over Taiwan would be lengthy and costly, domestic pressures in the United States could strengthen calls for restraint in U.S. foreign and security policy. 

Over time, such pressures – particularly within the Republican Party – could shape the strategic calculations of future administrations. For Beijing, that possibility could translate into greater freedom of action in its own region and beyond.