So it is good that Japan is making their significant military power available to fight at our side:
Japan took a historic step away from its post-war pacifism on Tuesday by ending a ban that has kept the military from fighting abroad since 1945, a victory for Prime Minister Shinzo Abe but a move that has riled China and worries many Japanese voters.
The change, the most dramatic policy shift since Japan set up its post-war armed forces 60 years ago, will widen Japan's military options by ending the ban on exercising "collective self-defense", or aiding a friendly country under attack.
When China had little power projection capacity, this wasn't a big deal. We didn't need anybody's help to hold the western Pacific.
And if the Soviet Union wanted to attack us, they pretty much had to attack Japan to get at us. And there was no legal issue with Japan accepting our help.
But the situation had evolved to the bizarre situation where if North Korea launched a nuclear missile at an American target not on Japanese territory, Japan legally could not engage it with their anti-missile systems.
More broadly, if China attacked American forces in the western Pacific but avoided striking any Japanese territory, Japan could not legally respond to help us fight China even though a Chinese defeat of America would obviously harm Japan's security.
Japan is ending that ridiculous legal constraint. Which is why China is complaining so loudly.