The capture of the tanker is the latest episode in escalating tensions between Iran and the West and comes at a particularly vulnerable time for Britain, where the contest to replace Prime Minister Theresa May has all but paralyzed the government.

The U.S. has offered to share intelligence and coordination to help other nations protect their vessels in the Gulf, but it made clear that its role would be limited.

What’s next: Boris Johnson, who will most likely be the next British prime minister, has said he wants to avoid a confrontation with Iran. But he is famously unpredictable and has sought closer ties with President Trump, who set off the current confrontation by withdrawing the U.S. from the global nuclear deal with Iran last year.

Go deeper: Both an audio recording of the exchange between a British warship and Iran’s forces and a video of the seizure were released on Sunday.

Mueller hearings loom over Washington

Robert Mueller, the special counsel, is heading to Capitol Hill on Wednesday.

Democrats hope that during five hours of nationally broadcast testimony, Mr. Mueller will focus the public’s attention on the findings of his 22-month investigation — either to jump-start a stalled impeachment push, or to severely damage President Trump’s re-election prospects.

Go deeper: Some Republicans are advocating a gentler approach to close the door on his inquiry. Here’s how they’re preparing for the showdown.