Why Syria and the wall funding was a 4d chess move:

Trump was gaming them. Most of the democrats were already out of town for christmas.

He waited until they had a republican quorum in the house.

The house had the choice of passing it or cancelling all their holiday plans and flying back into town to do battle with trump.

Who would have won anyway cause…

Whatever would trump do with the sudden budget surplus that canceling syria and afghanistan will cause? Might it have gotten turned into wall?

The play here was pretty obvious.

Heads, trump wins, tails, the democrats lose.