Well, there are atheists in foxholes, but maybe the reason there aren't that many is because many military commanders are hostile toward them.

The NY Times reports on the case of Specialist Jeremy Hall:

When Specialist Jeremy Hall held a meeting last July for atheists and freethinkers at Camp Speicher in Iraq, he was excited, he said, to see an officer attending.

But minutes into the talk, the officer, Maj. Freddy J. Welborn, began to berate Specialist Hall and another soldier about atheism, Specialist Hall wrote in a sworn statement. "People like you are not holding up the Constitution and are going against what the founding fathers, who were Christians, wanted for America!" Major Welborn said, according to the statement.

Major Welborn told the soldiers he might bar them from re-enlistment and bring charges against them, according to the statement.

...

At the July meeting, Major Welborn told the soldiers they had disgraced those who had died for the Constitution, Specialist Hall said. When he finished, Major Welborn said, according to the statement: "I love you guys; I just want the best for you. One day you will see the truth and know what I mean."

So Jeremy Hall decided to sue, which I think any reasonable minded Christian would have done if they'd tried to form a Bible study group during their private time and a superior officer had crashed the meeting and told them they were a disgrace and that he would bring charges against them.

After filing the lawsuit, he started receiving threats, so he was transferred out of Iraq, back to the US to Fort Riley.

Nice, huh? I wonder if any of these dickheads who threatened him have ever actually read the First Amendment.