1. Tensions between Iran and the West are simmering once again.

Britain threatened Iran with “serious consequences” for seizing a British-owned oil tanker, above, and warned ships to stay out of the Strait of Hormuz, a key shipping route for the world’s oil supplies. The British defense minister said the tanker had been intercepted in Omani, not Iranian, waters and called the seizure “a hostile act.”

The incident comes at a particularly vulnerable time for Britain: Prime Minister Theresa May is expected to resign on Wednesday, and to be replaced by Boris Johnson. But the leadership contest within the governing Conservative Party has all but paralyzed the government and frustrated voters.