Hopefully it'll go up because he does a good job, and not because of brainwashing. If it goes up, of course.
He will do a horrible job, but it will go up, at least for a while. There are certain things one can do to have the country have a bit of a high for a while. Of course, long-term consequences will be awful, but early on it will seem like things are going well. Afterwards, when the withdrawal starts, he will start a war and have a jingo explosion. When the war will start going wrong, he will withdraw and declare himself a peacemaker and/or winner (to the general adulation) - only to start another war in a completely different place shortly thereafter. At some point it will all boil over, but it will take a long time.
