U.S. and Russian navies search for the downed drone, Washington hunts for ammo, China looks for trouble with Japan and North Korea stirs the pot.

(Originally published March 16 in “What in the World“) Russia said it would try to retrieve the U.S. Reaper drone its fighter jets downed this week over the Black Sea. That will pit it against the drone’s unhappy owners in the U.S. military, who are already scouring the Black Sea’s depths for their fallen Reaper.

There’s no limit on how long the search could last or what else they might find down there: the Black Sea’s depths hold too little oxygen to support life, making them a watery time capsule for anything that has the misfortune to sink there. In 2008, British scientists found the wreck of a Greek ship believed to be 2,400 years old lying intact on the bottom. Like the Reaper, it sank in waters more than a kilometer deep.

The only thing more elusive than the wreck of the Reaper may be the ammunition the U.S. is promising Ukraine to fend off a Russian spring offensive. Both nations are running out of shells and air defenses. It’s unclear how the U.S. plans to honor its pledge given the backlog facing manufacturers.

The East China Sea, by contrast, isn’t as deep, but stands to become just as stormy after China’s coast guard on Wednesday steamed into Japanese waters around the disputed Senkaku Islands to intercept Japanese vessels it said were making “an incursion.” The Senkaku Islands, claimed by both China and Taiwan as the Diaoyu islands, are a group of uninhabited rocky islets that Japan has held since Tokyo annexed them in 1895 during the first Sino-Japanese War. The U.S. held them after World War II but gave them back to Japan in 1972 along with Okinawa.

Next to the East China Sea lies the Sea of Japan, hapless victim of North Korea’s ongoing war against the ocean. Pyongyang on Thursday kept up its barrage, lobbing an ICBM into waters west of Japan just as South Korean President Yoon Suk Yeol heads to Tokyo for South Korea’s first summit with a Japanese prime minister in 12 years. Topping the agenda: the threat posed to both nations by China and North Korea.