If the enemy is in range, so are you. Friendly fire is the most accurate fire, due to their knowledge of your location and maneuvers. Don't look conspicuous, it draws fire. There is always a way. The easy way is always mined.
Professionals are predictable, it's the amateurs that are dangerous.
When you're not ready for them. Teamwork is essential, it gives them someone else to shoot at. If you can't remember, the claymore is pointed at you. The enemy diversion you have been ignoring will be the main attack. A 'sucking chest wound' is nature's way of telling you to slow down.