Nope, it has quite a few turns. Second part of the first mission where you work with the Nin.
That one is insane, but I think I can help. Duck your rockets under the long window at the top and have them quickly pop out of cover to fire at the start of each turn. This leaves you with three soldiers for three doors. If the enemy sets so much as a foot inside the lift you immediately lose, so you need to position the shotgunners to cover the approach to the door. Ignore the lower-left door unless you see someone heading for it, and put one shotgunner at each remaining door. Your rifleman is pretty useless; if he defends the inside he'll get shotgunned, if he shoots out he'll get sniped. Use him as you will, and don't give up if he dies.
There are no perfect solutions, unfortunately. Nowhere on your lift is 100% safe, but there are two good spots to cover the doors: ducked on the far left side of the upper window (so that your soldier is covering the right side door and out of sight of all windows), and in between the two walls on the left side, covering one door or the other. Use your rockets as offense and your other soldiers as defense, and be prepared to get creative if the enemy gets up to the lift's walls. There's no law you need to stay inside the lift but leaving usually results in death.