A couple of iron hand strong will political leaders:
Took Hitler 10 years to destroy his country.
Took Ergodan about 5 years to ruin his country.
Trump might only have 4 years, but he is hard at work to accomplish his task, waging war against his allies and insulting them, comploting with the enemy, just taking horrible decisions on a dialy basis.
Iron hand strong will head of states / head of government are going faster and faster!
How long will it take from strong will iron hand "I will not back down I will get a better deal" Trump to ravage the USA economy?
My bet is before 2020 his task will be done, he will have single handedly ruined the USA, and of course he will blame someone else :)
Wait and see.