> How would they stop them? Invade and depose the democratically elected president, then setup a puppet government to do their will?

Are you at all familiar with Latin American history? That's hardly an unprecedented US response to ideological, commercial, or other differences.

Lots of jokes about invading or overthrowing the gov't but I believe they would just cut El Savador off from the U.S. financial system entirely.

The same thing was applied to a handful of Chinese and Hong Kong officials. See: https://www.scmp.com/economy/china-economy/article/3098691/h...

> The extensive and complex nature of the US financial system means non-US international banks would most likely comply with the Hong Kong sanction requests to safeguard their overseas network and US dollar-denominated transactions that are ultimately cleared in the US by passing through the US Clearing House Interbank Payments System (Chips).

My understanding is that if you do not comply you are basically unable to trade in USD.

That'd be extreme, but there would be all sorts of possible ways.

See eg

https://www.theguardian.com/commentisfree/2014/oct/23/gough-...

Threaten to cut diplomatic ties, prevent US banks from doing business with El Salvador, prevent USD remittances, make transferring BTC to El Salvadorans illegal, etc.

You got it!

It wouldn't be the first time...or second, or third, or fourth, or fifth...

Source: https://www.amazon.com/Overthrow-Americas-Century-Regime-Cha...