For the last decade, the American military has been suffering a growing chaplain shortage. The military needs over 50 percent more chaplains just to fill the gaps. Some denominations have it worse than others, with Roman Catholics perhaps the worst off, with less than half the priests they need for chaplains. The problem was present before September 11, 2001, and has only gotten worse since then. It's not just the reluctance to get sent overseas (most chaplains are married with children, except for the Roman Catholics), but also the trend for more clergy to be men doing it as a second career. The army does not accept new chaplains if they are older than 42, so that eliminates a low of newly minted, second-career, clergy.
The air force has the fewest problems. The navy, however, has had growing difficulties recruiting chaplains since the Cold War ended. The army is the largest service, with half a million active duty troops, and half a million reservists, and the biggest chaplain shortages. The army is taking most of the casualties in the war on terror, and has the most people overseas in combat zones. While there are some chaplain shortages in the active duty army, there are not nearly as severe as those in the army reserves. The army has called up a lot of reserve chaplains to cover shortages of active duty chaplains, which has made it difficult for clergy getting civilian jobs. Protestant congregations became reluctant to hire a minister who was a reserve chaplain, because so many are being called to active service. This caused many Protestant clergy to leave the reserves, making the shortages worse. The Roman Catholic has a growing clergy shortage in general, and now some priests are being ordered by their bishops to leave the military to fill growing shortages at the parish level.
Another factor is a change in the composition of the chaplains corps. It used to be that about a third of the troops, and a third of the chaplains, were Roman Catholic. Since these priests could not marry, they had more time for their military duties, and came to get promoted more often. No more. There has been a sharp decline in the number of Catholic men entering the priesthood in the last three decades. Thus today, while about 20 percent of the troops are Roman Catholic, only about ten percent of the chaplains are. There has also been an enormous growth in the number of denominations that chaplains are recruited from. Sixty years ago, there were ten denominations that supplied chaplains, while now there are over two hundred. The fastest growing denominations are evangelical Christians, and their aggressive preaching and recruiting style has caused friction among the troops, and with other chaplains. Military regulations prohibit chaplains from trying to convert others to their sect. Some groups cannot handle this one, and that creates problems. All of these factors have also contributed to the chaplain shortage in the army reserves, and, despite vigorous efforts, there is no cure in sight.