Unsustainable debt is usually inflated away for countries whose debt is in currency they can print. The country prints money to pay the debt, and the currency is eventually devalued. Currency devaluation has happened to the UK, Germany, France, Italy, Austria, Greece, Spain, China, India, Argentina, Venezuela, the Roman Empire, ancient Egypt, etc.
War increases government spending and inflation. So war isn't usually the solution to inflation. But if war can get a country out of paying debts, or be a mechanism for seizing substantial foreign assets, or if it can distract the citizens from other giant internal turmoil . . .
That $100,000 of total US public dept per person is $200,000 per working person. It is $250,000 per US household.
Here is US public debt over time: