The foreign tax credit is provided to prevent the double tax burden when your foreign source income is taxed by both the United States and the foreign country.

You just submit that you already paid taxes on that income to a foreign government and then no additional US taxes (to a limit, I beleive).

It's not that simple. There are a lot more details, but at a minimum you will still need to pay US taxes to the extent that the foreign government taxes at a lower rate. You'll also often still need to pay state income taxes.

That brings up very interesting questions:

To which state would one owe taxes to since you're no linger a resident?

Similarly, Americans abroad vote, but ppl in DC (not a state) cant?

Can I avoid state taxes by sojourning in DC before moving abroad?

The answer depends on how your specific state defines tax residency (for example California is notoriously difficult to escape).

Generally the rules will be something like you remain a tax resident of your old state, regardless of how long you stay abroad, until you establish a new permanent tax residency (whether in a new state or country).

What I eventually did is return to the US, sign a 1 month lease in Florida so I could get a drivers license and register to vote, and then return abroad. According to my tax accountant, that was enough.

Americans abroad shouldn't pay taxes (since they get basically no benefits) or vote (why should those who live abroad affect the laws they are, largely, not subject to?)

Canada's rules are like that and I like it!

Americans abroad get a very valuable guarantee though. If shit hits the fan the full force of the US Military and Government is around to help out. They also are a last resort for Americans in emergencies abroad. Emergency assistance, flights and travel back home, etc.

It's not like we give up everything but leaving the country.

It's not much of a guarantee when it depends on the administration in charge. Recent debacles come to mind first, but the willingness of the government to help (in particular, with your mention of the military) is extremely variable.

Don't forget consulate and embassy services.

And your citizenship allows you to get visas/dual citizenships that you wouldn't have access to if you weren't an American citizen. An American passport is pretty valuable, even if you don't live in America.

This is all less relevant if you move to, say, the EU, but it's still worth noting.

Why is America the only country that taxes people who have citizenship but aren't residents?

The only one, guys.

Also Eritrea… uh but only at 2%.

Because people in the us hate taxes and their purposes and thus don't tax the residents enough?

The average working American only resents high taxes when they can't see the effects of their taxes in their local communities.

If your property tax keeps going up but nothing gets better in town, are you gonna trust the tax man?