I would imagine a bit of both. Perhaps he's strengthening our military by not spreading them to (ungrateful) areas that they are no longer needed.
Nice way to say f-you to Germany. I am concerned about some of the withdrawn troops being from Asia, though, with N. Korea and all that.
With most of the focus on the "no longer needed" I would presume.
However the (ungrateful) certainly could be a lesser factor in the decision.
Everything we would need to do to North Korea can be done from the sea. The Navy is how the United States projects its power. Ground troops in South Korea are sacrificial lambs.
Those 37,000 troops are hostage to a North Korea with nukes. Getting them out of there should be a priority. If South Korea with its industrial and financial strength cannot defend itself from a North Korean conventional attack then our 37,000 troopers will not add much to their effort and their presence will be an impetus for the irrational North Korean leader(s) to go nuclear.Besides I am certain that we could find very useful assignments for 2ID and its supporting units.