He had killed plenty of men with his country's blessing in the past, but this time pressing the trigger meant breaking the most sacred bond of society; he'd just committed murder.”
-- Narrator (Prologue )

Importance: This is the description immediately after Reece shot Boykin. This shows that Reece knows the difference between this and the men he has killed in battle, but that line seems to become thinner as Reece seeks revenge.

How can I go home and face my family when twenty-eight Rangers, four aircrew, and thirty-six SEALs of my Task Unit are going home in boxes. That's war, Reece.”
-- Reece (chapter 6)

Importance: This is part of Reece's thought process as he prepares for the trip back to the United States. The effect of war is one of the novel's themes.

It doesn't make any sense for them to have done all of this and left you alive, which means they probably intended to kill you...
-- Katie (14 )