A Time opinion article by US Senator Tim Kaine warns that any attempt to pull the United States out of the North Atlantic Treaty Organization (NATO) would amount to “national self-sabotage”, even as legal safeguards prevent a unilateral exit.

Kaine, a Democratic senator from Virginia and former vice-presidential candidate, co-authored bipartisan legislation — alongside now Secretary of State Marco Rubio — that bars any US president from withdrawing from NATO without congressional approval. The law, passed in 2024, reflects what he describes as a long-standing bipartisan consensus on the alliance’s importance.

In the article, Kaine argues that NATO remains “an indispensable force for democracy and peace” and a cornerstone of US national security, enabling global military reach through allied bases and deterring adversaries.

The piece comes amid renewed criticism of NATO by US President Donald Trump, who has threatened to withdraw from the alliance and accused it of failing to support US actions in the Iran conflict. Kaine writes that such rhetoric undermines the alliance and makes “America and the world less safe.”

He criticises the Iran war as a unilateral decision taken without consulting Congress or allies, noting that NATO members have largely stayed out of the conflict due to concerns over its consequences and economic strain.

Despite tensions, the article highlights improvements within NATO, pointing out that all 32 member states now meet the benchmark of spending at least 2% of GDP on defence — up from just five countries in 2011 — with a new target of 5% agreed over the next decade.

Kaine also underscores NATO’s broader role beyond military cooperation, citing its contribution to economic integration, democratic values, and the rules-based international order. He warns that weakening the alliance could create a vacuum for rivals such as China and Russia.

While stressing that Trump cannot legally withdraw from NATO without Congress, Kaine cautions that continued efforts to undermine the alliance could still have serious consequences.

He concludes that any attempt to dismantle NATO would be a “tragic error” that risks US security, but could also prompt Congress to reassert its authority in defence of the alliance.