US and Iran trade strikes in biggest test of truce as NATO leaders meet

NATO leaders gathering in the Turkish capital on Wednesday were supposed to be discussing defense spending and continued support to Ukraine, but US President Donald Trump’s decision to launch new strikes on Iran overnight will likely overshadow proceedings.

Iran vowed a “crushing response” to the US strikes on Iranian targets –– that were prompted by Iranian attacks on commercial vessels –– and quickly fired drones and missiles at Gulf neighbors Bahrain and Kuwait, which both host US military bases.

The exchange of fire poses the biggest threat yet to the fragile ceasefire between the two countries, renewed with a memorandum signed last month.

It’s not the first time the two sides have traded strikes since the memorandum of understanding was signed, but the US move to also reimpose sanctions on Iranian oil sales is an escalation that will likely complicate the next round of negotiations toward a long-term peace deal.

The US strikes were launched shortly after Trump left a dinner hosted by Turkish President Recep Tayyip Erdogan and attended by the NATO leaders, who have been trying to smooth relations with the US leader and prove that Europe is a strong partner to the US.

NATO allies on Tuesday were keen to showcase progress on increasing defense spending and shifting dependence away from the United States. Trump, who considered skipping the annual meeting altogether, has renewed his criticism of NATO and what he sees as a lack of support among allies for his war in Iran.

The strikes also come amid ongoing questions about the future of the US military presence in Europe, with Trump hinting at further US troop reductions. The fear among some allies is that Trump, angry that members of the alliance failed to join him in the war against Iran, will use the conference to announce major shifts in US support for the 77-year-old alliance.

CNN’s Kevin Liptak and Ivana Kottasová contributed reporting.