The current heavy use of satellite communications by the U.S. Department of Defense did not happen overnight. Most of it happened in the 1990s. Between the 1991 Gulf War and 2003, Department of Defense use of satellite communications grew 30 fold. It's grown even faster since then. But what really got this trend moving was a smart business move by Defense Department bureaucrats in the late 1990s. Back then, the Department of Defense brokered a deal to save the bankrupt Iridium satellite phone network, by having a firm buy up the failing business cheap. The Department of Defense made this work by giving the new Iridium a contract that provided lots of inexpensive time on Iridium phones for American troops. The Department of Defense was able to provide lots of satellite phones, and cheap rates (25 cents a minute) for the troops.
Iridium has since become a viable commercial enterprise, with 360,000 subscribers. New technology, Iridium NEXT, will be available in four years. In the next seven years, a new fleet of 72 Iridium satellites will be in orbit, replacing the current 66. This original fleet, in service since 1998, were only supposed to last seven years. But they proved more resilient. The NEXT birds will provide higher data speeds (1 Mbps), Internet support and other requested features.
In the two years after September 11, 2001, the use of Iridium phones by troops went up 48 fold. The Iridium phones were a key communications tool during the Afghanistan war, and since then thousands of phones have been distributed to unit commanders and special operations forces. Over all, communications traffic on all Department of Defense networks went up over five fold between September 11, 2001 and late 2003. As a result, the Pentagon has spent over $30 billion since then getting more troops, and more uses, on to the military satellite network.
Satellite communications are much preferred by the troops, since they enable instant communication with anyone, anywhere, and are not subject to the range and obstacle restrictions of FM and AM radios. Although satcomms are more expensive, they pay their way by making the troops more effective.