"To the Virgins, to Make Much of Time" is sometimes referred to a as "carpe diem" poem. The phrase, from Horace's Ode 1.11, means "seize the day," and the concept was by no means a new one for a poem even when Horace wrote the Odes more than two thousand years ago. The poet apostrophizes the virgins directly and tells them to make the most of their youth, for it will not last long.
"The Terrorist, He Watches" has a simple, declarative tone. No one is addressed directly. The terrorist has planted a bomb in a bar and retired to a safe distance. The bomb will detonate in four minutes. The terrorist watches people go in and out. He knows that it is death, or at least serious injury, to be in the bar at 1:20, but he can no longer influence who is there and who isn't, nor is there any indication that he much cares.
Both poems are about the passage of time. The first explicitly exhorts the virgins to enjoy their youth, for it will not last long. It will, however, probably last a lot longer than the lives of the men and women who are in the bar when the bomb explodes. They cannot know that they will die today, but they clearly do know that they are going to die at some point. The poem does not contain an explicit message and therefore does not ask whether they seized the day and made the most of their lives. The reader, however, reflecting on their sudden, random deaths (and on all the sudden, random deaths in the world, whatever their most proximate cause), can scarcely avoid doing so.