We stay there because it is the only footprint we have left anywhere in continental Asia. I'm sure that you can see the value in that.
The United States is engaged in a police action with north Korea that is in a state of cease fire. It never officially ended. It is ongoing.
Foot print in Asia is not the reason. We are there as part of the UN mission in the ongoing police action mission. Negotiations are still in progress at Panmumjon
We have major troop and air deployments in Asia..... in Afghanistan