This is the last push towards the end of the Silent Talon mission. After clearing out the area in front of the enemy base using the Warhound, you will be free to proceed through the rest of the level and up to the weapons storage facility. When you are certain that the area is clear, rush down the slope ahead and take cover. Look to the right, at the large shuttered door. This door will soon open and reveal another group of enemies, one last desperate attempt at keeping you from discovering what lies inside of the warehouses ahead. As these enemies run out, another, smaller group will run out of the second floor and fire at you through the slits in the windows. Take control of the Warhound and target the enemies on the ground as they try to advance on your position. Blow them all up with the mortar and then focus on the hostiles on the second floor. By now one of the enemies will have taken up a position behind a mounted machine gun. Launch a guided missile to take his out first, and then clear the second floor of any remaining hostiles. Keep firing until the game notifies you that you have cleared everyone out of the area.
When the area is cleared, regroup with the rest of your team and head to the doorway from which the last group of enemies attacked. When you reach the inside of the base, immediately turn to the left to find an ammo crate. Restock on ammo and approach the large blast door at the end of the hall. Overlord will crack the door for you and let you inside of the warehouse. When your proceed inside, you will find tons and tons of heavy weaponry, enough to wage a war against the US. You will receive the order to destroy the weapons. Approach the white rings next to several of the missiles and place a C4 charge on each of the marked areas. After all of the charges have been place, you will have three minutes to leave the warehouse before the explosion sends the whole place up in flames. You should be able to make it easily enough.
Turn around and sprint back outside. As you reach the outdoors, take cover. The helicopter that fled the scene earlier will be back with a vengeance, and it will begin to fire upon you and your team. The helicopter will begin to drop off enemies, seemingly unaware that the whole place is rigged to blow any minte now. Immediately take control of the Warhound and bring the helicopter down with a guided missile. Hopefully this should stop it from dropping off some of its infantry. Target the rest of the ground troops with the Warhound’s mortars in order to finish them off and clear a path ahead. Unfortunately, a light vehicle will drive in just as you finish mopping up the footsoldiers. Destroy the vehicle with your mortars, too, and you will really have cleared a path away from the base. Run out of the area and towards your new waypoint. Even if you haven’t managed to clear all of the enemies by the time the countdown gets under one minute, you should still seriously consider getting out of dodge. The base is going to blow and you need to be at the waypoint. If any enemies get caught in the blast, it’s their own fault.
As you reach the waypoint and the base blows up, you will receive the Achievement/Trophy for mission completion. You may now proceed on to the next mission in the game.