Oh really? What's your 'proof'? There are a tremendous number of stories validating that saying.
http://www.ffrf.org/foxholes/
http://atheism.about.com/library/FAQs/ath/blathm_urb_foxholes.htm
http://ca.answers.yahoo.com/question/;_ylt=AlyvVcBHgMc17kCM4SumEJLpFQx.?qid=1006053112726
http://atheism.about.com/b/a/133061.htm
http://www.atheistfoxholes.org/about.php
(from the last) Would God even want people to believe merely because they were under great pressure and very afraid? Can such a faith lead to a life of faith and love which is supposed to be the foundation of religions like Christianity? Is the claim that there are no atheists in foxholes meant to imply that atheists aren't "really" disbelievers and actually harbor a secret belief in God? Perhaps, but it is a false implication and can't be taken seriously. Is it meant to imply that atheism is inherently "weak" while theism represents "strength?" Once again, that may be the case - but it would also be a false implication.
Besides, even if it were true that there were no atheists in foxholes, that's not an argument against atheism, it's an argument against foxholes.