September 11 instantly reoriented military training toward anticipated combat.

Evidence

Everybody in his family was all right, but everyone—in the family, in the military, in the world—also knew what the attacks meant. The training at Camp Lejeune is normally physically demanding, but that wasn’t the half of it now. The atmosphere had immediately intensified as the soldiers were learning battlefield skills that they and their teachers now expected them to be using in short order. What everyone understood was the inevitability of war, and the new soldiers all paid very close attention. — Moustafa Bayoumi, How Does It Feel to Be a Problem? Being…, 210