Welcome to the NewsHour. The tenuous truce between the U.S. and Iran was tested today as American ships clearing a lane in the Strait of Hormuz came under fire and sank Iranian boats.

Also today, Iran fired drones and missiles at a key oil terminal in the United Arab Emirates, spooking markets and raising concerns that the war could resume.

Nick Schifrin begins our coverage.

Today, the war in Iran threatened to reignite.

The Islamic Revolutionary Guard Corps, or IRGC, fired missiles and drones and deployed small speedboats

like these to attack U.S. guided missile destroyers, trying to clear Iran's chokehold in the

Strait of Hormuz, and the U.S. fired back, said the military's top Middle East commander

in a briefing to reporters.

The IRGC has launched multiple cruise missiles, drones and small boats at ships we are protecting.

We have defeated each and every one of those threats through the clinical application of defensive munitions.

Those munitions used by jets, ships, and more than 15,000 surf members conducting Project Freedom.

It's designed a clear lane through which dozens

of ships currently stuck can pass through the strait under a defensive umbrella with a U.S.

official compared to zone defense rather than the man-to-man defense of an escort.

We have multiple layers that include ships, helicopters, aircraft, airborne early warning, electronic

warfare.

We have a much broader defensive package than you would have ever if you're just escorting.

Iran's campaign in the strait has damaged nearly 30 vessels since the start of the war.

Their charred and rusting remains littering the strait and ensuring Iran's chokehold.

Today, two U.S. destroyers entered the strait and two U.S. flag commercial ships pass safely.

The U.S. goal to convince shipping and insurance companies they too can send their vessels through the strait. Over the last 12 hours, we've reached out to dozens of ships and shipping companies to encourage

traffic flow through the strait, consistent with the president's intent, to help guide ship

...