For the first time in 70 years, Japan is rebuilding its military. And with tensions on the rise in the Pacific, the U.S. could be forced into a war.

After Japan was defeated in World War II, the country was forced to disarm and swear off military capability, outside of self-defense, ever again. Over time, that pacifism became part of the Japanese psyche. But with nationalism on the rise around the world, Japan hasn't been immune to the political tide.

In recent years, China has been amping up tensions with the U.S. and its allies by claiming, constructing, and militarizing islands in the nearby South China Sea. And with the looming threat from North Korea, Japanese nationalists are getting ready to protect their country.

Japanese Prime Minister Shinzo Abe and his backers are rethinking the country’s previously peaceful stance and moving to restore Japan’s military might. The country's 2017 military budget was its biggest ever, and if local hostilities boil into conflict, the U.S. is expected to play a specific role.

“Japan fully depends on the strategic deterrence and strike capabilities of the United States if China really goes for military action,” said retired Adm. Yoji Kada, who was once the commander-in-chief of Japan’s self-defense fleet. “The cost they are going to pay is very bloody. They know that.”