Veteran mode cuts life expectancy to three or four shots before dying. However, Veteran mode does not improve the enemy's aim or strategy so use small blocks or small bulges of hills as cover and crawl. Since you do not get points for kills, do not take the Nazis head on. Let your allies lay some fire, if you have any. If not, throw a smoke grenade and shift between crouch and crawl positions, laying cover fire and stall some time for the smoke grenade to spread before the Nazis rush in. Use this smoke cover to fall back to the nearest safe position where you can regroup or hideto pick the Nazis off from a distance.
When playing campaign mode on the Veteran difficulty in, always take cover. Wlways go prone or get behind a wall whenever you reload or get hurt badly. Also, use your smoke grenades wisely as you will need them to get past certain parts of the game, such as when clearing houses or getting past turrets.