1- Most of these countries have debt in their own currencies, and all of these countries have strong sovereignty over their currencies. They can control the liquidity, the value, the interest rates, the tax rates, etc, of this currency. So this debt means little. Murka has an even better position since it has the world currency, which means it can export inflation to other countries. Argentina is an example of a dire situation, since they keep making debt in other currencies. Also reminder that China and Japan owns most of murka's debt.
2- Having trade deficit, budget deficit, increase in debt are a problem and will kill most countries. Having only one or even two of these is bearable for any developed country. Murka manages to have the three of them, but then again it has the world currency, it's a country that is sovereign in food and energy, so it simply doesn't have to worry about inflation. Food inflation will collapse any government because it affects people directly, but at the same time food can be sourced from many countries. Nobody goes to war over food these days. Energy inflation due to fossil fuel imports has a more indirect effect since it affects businesses, not people, but this will cause businesses to stop hiring, increasing unemployment (and also loss of tax revenue). But at the same time sourcing energy abroad is much more problematic. China is working hard to be energy sovereign. Meanwhile eurangutans are undermining their own interests by forbidding any kind of native energy source.