A key factor in lowering American casualties in Iraq and Afghanistan is the ability to quickly build bullet, rocket and bomb proof shelters. This has been made possible by using existing commercial products (like HESCO barriers, originally developed two decades ago for flood control) to armored cargo containers and erector set like kits for quickly (within minutes) building protection for troops at checkpoints.
The standard 20 and 40 foot shipping containers are regularly retained, after they arrive at a combat zone and used for work and living areas. This actually began during the 1991 Gulf War, and has only gotten more organized since then. It was quickly learned that adding lightweight bullet and blast proof panels made these containers safe places for troops to eat, work and sleep.
And then there are commercial products. HESCO developed, back in 1990, portable barriers, which were basically just collapsible containers that, once opened up and filled with dirt or sand, were blast and bullet proof. Thus troops could roll into an area with a few trucks and a back-hoe. Within hours, the blast walls are up and filled with dirt, and covered with night vision vid cams and other sensors.
The blast walls, and similar protection on the cargo container offices and living quarters, protects troops from the largest weapons (122mm rockets) used by terrorists in Iraq. The 122mm rocket carries about fifty pounds of explosives, and experience has shown that the HESCO type barriers will keep people inside safe from that. The barriers are cheap, with the largest one (7.2x7x91 feet, 2.3x3.3x29.3 meters) costing $3,500.
The latest wrinkle is for checkpoints, where you have to set up and break down protection quickly. For $57,000 you can get a McCurdy Armor set. The stackable armor, including some with a ballistic window, allows troops to assemble a small shack, or a wall, in about ten minutes. The armor is bullet proof and bomb resistant. The lightweight armor sections can be stacked in the back of a hummer.
The quick appearance of these bullet, rocket and bomb barriers impresses the Taliban, and discourages the terrorists (who know that their chances of putting the hurt on anyone so protected is quite low.) While this instant protection is safer, the instabases are not always comfortable. Often, the barriers are placed around some existing buildings that have not been used for a while, or just empty land. The troops set up camp wherever they can, and live rough for weeks at a time. Rough, but safe. Even if only while manning a temporary checkpoint.