Spain in the 1500s, the Netherlands in the 1600s and the British empire in the 1800s are good examples of countries considered too big to fail that they eventually crashed and burned and lost their world leader statuses rather fast.
In all three cases over reliance on new debt to fund stuff, disappearance of the middle class, and abusing their dominance (military and/or economic) made them crumble as other countries steered away from dealing with them.
Spain in the 1500s, the Netherlands in the 1600s and the British empire in the 1800s are good examples of countries considered too big to fail that they eventually crashed and burned and lost their world leader statuses rather fast.
In all three cases over reliance on new debt to fund stuff, disappearance of the middle class, and abusing their dominance (military and/or economic) made them crumble as other countries steered away from dealing with them.