Who would benefit the most if The United States crashed and burned?

No one asshole. The world falls if the US falls. Love it or Hate it, the world depends on the USA.

Why would the entire world fall if the US fell? Please expound.

The world once depended on Babylonians, it fell and the world kept on going.
The world once depended on Persians, it fell and the world kept on going.
The world once depended on Romans, it fell and the world kept on going.
The world once depended on Greeks, it fell and the world kept on going.

Why would this time be different?

The Global economy, our unparalleled military strength. What, you gonna hookup with China, or Russia? They are going to lead this world? China doesn't give 2 shits about it's people, much less any other country.

Keep telling yourself you don't need the US to be strong, if that's what you need to sleep at night.....

Welcome to the new ice age. SNOWIE

In the simplest terms, everyone else.

NWO/Globalist 101. Bring down the strong, redistribute the spoils and level the playing field.

chinas market would prolly go down about 10% short term, explode after they send 400 million to cleanse the land.

The Global economy depends upon the US economy. The Crash of 2008 (for example) started in the US and spread around the Globe.
It is a unintended consequence of Globalism.

As for who would benefit, it is the NWO crowd. Which is basically the Elite.

We in the US are not willing to follow their directions and submit to them. So the only way to get it done is to crash the US and remove it as an obstacle.
Since we resist them, other countries resist them also.

A selling point to creating the NWO system would be that it would not allow one country's economic dominance and thus avoid another world wide economic disaster, caused by a single nations mistakes. Even if it was the NWO group that engineered the crash in the First place.

Since the NWO would be making the rules and enforcing them on everyone (That means slavery for everyone, except the chosen few).