US marines
I do not know where Syeda Akthar gets her information from, but many of the facts in her letter about the US marines are not right. First of all, the US marines are not less privileged than the army. In fact, the US marines are considered an elite force. That they write such things as "Search and Kill" and "Blind Killer" on their vehicles is not a sign of bloodlust, but of their confidence and high-motivation, of doing what they were trained to doto fight a war.
Second of all, Timothy McVeigh was not a marine, but an army infantryman. And his Gulf War experience had nothing do with the bombing of the Murrah Federal Bombing, but his growing anti-government view had.
Soldiering does produce mental stress, and can lead to violent behaviour like Fort Bragg but to wash the US marines with such a wide brush is unfair.