An Indian-American Congressman has warned Donald Trump that any attempt to withdraw the United States from NATO without congressional approval would be illegal and could severely undermine national security.

In a strongly worded letter, Raja Krishnamoorthi expressed “deep concern” following Trump’s recent remarks suggesting he was considering pulling the US out of the alliance. The comments reportedly came after Trump’s meeting with NATO Secretary General Mark Rutte at the White House.

“Any unilateral US exit from NATO would be both strategically reckless and blatantly illegal under current law,” Krishnamoorthi wrote, adding that such rhetoric risks emboldening adversaries while weakening America’s global standing.

The Congressman cited Trump’s statements indicating dissatisfaction with NATO, including remarks that the US “doesn’t need” the alliance and suggestions that congressional approval might not be necessary for withdrawal.

Krishnamoorthi rejected that claim, pointing to provisions in the National Defense Authorization Act (NDAA) for Fiscal Year 2024, which explicitly bar any president from unilaterally exiting NATO. Under the law, withdrawal requires either a two-thirds majority vote in the Senate or an act of Congress.

“This reflects Congress’s constitutional role in treaty matters,” he wrote, emphasizing that the provision enjoys strong bipartisan support.

He warned that even discussing a potential withdrawal could have serious consequences for global security. NATO’s strength, he argued, depends not only on military capability but also on the credibility of US commitment to collective defense.

“Abandoning NATO would undermine US credibility with allies and partners worldwide, embolden adversaries such as Russia and China, and weaken collective deterrence at a time of heightened global instability,” Krishnamoorthi said.

Founded in 1949, NATO remains a cornerstone of US and European security policy, with its collective defense clause—Article 5—serving as a key deterrent against external threats.

The Congressman urged Trump to reaffirm the United States’ commitment to its alliances, warning that decades of bipartisan leadership in maintaining global stability could be eroded by unilateral actions.

The exchange highlights growing political tensions in Washington over foreign policy direction, particularly at a time of escalating global conflicts and shifting geopolitical alliances.