On Feb. 1, China’s new coast guard law went into effect. It allows the Chinese coast guard to fire upon vessels around the Senkaku Islands in the East China Sea, which are claimed by both China and Japan, or ships around a number of reefs and islands in the South China Sea where Beijing has contested claims with the Philippines, Taiwan and Vietnam, among others. The new law could escalate tensions in the region, and Japan is now debating how to respond.

What is the structure of China’s coast guard?

A 2020 U.S. Department of Defense report notes that, over the past decade, China has more than doubled the number of large coast guard patrol ships over 1,000 tons, from about 60 in 2010 to more than 130 as of last year. That makes the Chinese coast guard, dubbed by some as China’s second navy, the largest in the world, the DOD says.