1. They have the biggest debt because they have the largest GDP. They use debt as an instrument to fund growth.
Thats is called a ponzi in other terms, And how is that growth going? Debt reaches a point that cant be undone... Hence fails
No, a ponzi scheme doesn't generate any real growth, it takes new payments to pay off investors.
America's growth is a quantifiable number, it's GDP. Without loaning money, that growth would be slower or non-existent.