Call of Duty: Modern Warfare 2 (2009)

These videos should help you complete Loose Ends and The Enemy of My Enemy on veteran difficulty.

At Loose ends, when running away from the house to the LZ. Just hide at the Solar energy part to the left for couple minutes. I noticed no enemys were left when I came out couple mins later and just could get to the checkpoint at top of the hill easy withouth any mortars being fired at me.

If you're having trouble at the DSM download part of Loose Ends, you should know that the best place to camp and protect the DSM is in the back room on the main floor. There, you can easily see both the basement stairs, the front door, and the side door. Enemy flashbangs won't reach you. Be wary of grenades and get a large-capacity rapid-fire gun, like an M240 or a TAR-21. Abuse your Claymores and flashbangs if needed.

While on Loose Ends, you will find it easy. But after the download you are going to have to run your a$$ off to the chopper with Ghost. You will probably die on the first 2 tries on this part but eventually, if you start to go stealthy and use Flashbangs, you will complete this mission. Enemy of My Enemy is the hardest mission on Veteran in the game. You're in the middle of a war. Try not to get in the fights. Be quick and quiet. At the very end of the mission when your going uphill, you will have to fight. Luckliy for you, your teammates are waiting for you in a car. While in the car, Crouch often while reloading and locating enemies. Your driver will automatically die and you will have to take the wheel. Dont panic and just go slowly into the back of the plane. My brother paniced and went off course and died.