The Taliban have no shortage of military targets in Afghanistan. There are over a thousand military and police bases in the country now, many of them (400) for the nearly 150,000 foreign troops. The United States has spent nearly $5 billion, since 2002, in building these bases, while other NATO nations have spent over a billion. There is currently $200 million worth of base construction projects underway.
The bases vary greatly in size. The two largest bases alone house 29,000 troops. Bagram, outside Kabul, hosts 20,000, while Kandahar has 9,000 (soon to be about 30,000). Many of the bases are quite small, especially the combat outposts, and usually temporary. These bases involve little construction, but often use portable structures (HESCO barriers, tents, trailers and, cargo containers) for protection and housing. Many of these outposts can be set up or taken down in a few hours.
Larger bases serve as permanent headquarters for brigades or battalions. Some 300 of these bases are American, about the same number that remain operational in Iraq (where there were nearly twice as many two years ago). Most (except for those used by American trainers and advisors) of the Iraqi bases are being turned over to Iraq. All those Afghan bases eventually go to Afghanistan.
Over 130 private contractors carry out most of the construction. They often compete with each other to get jobs, and provide employment for tens of thousands of Afghans. Many specialists are foreigners, because there are not enough Afghans available with the needed skills. Many of the building materials come from Afghanistan, but most of the material (including all the many items that are not manufactured in Afghanistan) are stored and distributed from a warehouse complex in Uzbekistan. Here, construction materials from all over Europe arrive (mostly) by train, and are flown (in emergencies) or trucked across the border into Afghanistan. Contractors have access to the Uzbekistan complex via a website. The base construction and maintenance operation is one of the most complex aspects of the Afghanistan war you never hear about.