Op, I think USA want to be strong from any country of the World So USA did attack on Japan because Japan were progressing and USA could see if any country go ahead from USA . USA country is Dollar and USA is controlling all the World and if you talk about debt on USA government then I will tell you ,every government take debt and Thay is necessary for country growth but I know India is is super Economic power in east and they have no debt to pay but mostly countries are facing debt problem. But debt is due government bad strategies and corruption of politicians and when politicians will not do corruption,the country will stand on its feet but it is very difficult for every country.
Basically, US is still the number 1 power in the world and they have held this position for nearly 105 years since World War II, and what they are doing is finding ways to maintain their position against opponents like China. They do not see Japan as a rival because Japan is their close Asian ally and depends on them militarily.
As for debt to the Government, as you said, that is just the Government's strategy in balancing and promoting the domestic economy. In addition, I think it is a binding strategy of great powers towards other countries, and here it can be said that the US. The US always tries to make other countries indebted and dependent on them. As for America's public debt, I think those are just numbers because they are still the ones holding the world's money printing machine, they have more than enough power to pay off debt by printing money and exporting inflation to the world.
By the way, do you have any proof that India is debt free?