China is the only vertically integrated economy left. In a multipolar/bifurcated/low trade world they will be the strongest.

The NAFTA/EU trade blocks were extraordinarily strong, this Greenland business is exactly the kind of issue which can shatter the entire block. It benefits no one to give Greenland to the US, so they won’t do it without a fight. It provides no benefit to the US to take it.

The only thing that would really be settled by the US annexing another country on a presidents whim is the formal end of the U.S. separation of powers.