The history of the U.S., 2001-2008, in 2 sentences:

[warrior1]

http://www.eschatonblog.com/2012/09/elevated.html

Post-9/11 the worst people in the world, the worst most incompetent people in the world, were hailed as the strong daddies who kept us safe. After they let 9/11 happen due to gross incompetence and stupidity, and after they set in motion a chain of events which killed hundreds of thousands of people.

[Moonwalk]

2. Speaking from the stance of a writer, they're not very good sentences. Try this....

Original: "Post-9/11 the worst people in the world, the worst most incompetent people in the world, were hailed as the strong daddies who kept us safe. After they let 9/11 happen due to gross incompetence and stupidity, and after they set in motion a chain of events which killed hundreds of thousands of people."

My Revision: "Post 9/11 the worst people, those who's incompetence resulted in 9/11, were hailed as the strong daddies who kept us safe. From 2001-2008 these incompetents set in motion a chain of events which killed hundreds of thousands of people."

See? You want to move the part about causing 9/11 nearer to the beginning. This does two things: First, it creates a timeline within the sentence structure. In the original we are "post 9/11" in the first sentence then go back to pre-9/11, and the incompetence that resulted in it, in the second. This is jarring. Move that part up to the first sentence and it maintains the timeline: 9/11 and immediately after 9/11 in first sentence, and from 01-08 in second.

Second, the revised version gives it more punch because you prove why you're calling these people "the worst" and "incompetent"; you give evidence that you're right in calling them that right after you call them that. This also emphasizes the irony of viewing those who caused 9/11 as those who keep us safe--then in the second sentence, you offer up the further results of this view up to 2008, which, again, have more punch thanks to people knowing, right away, that these people's screw-up caused 9/11.

The two sentences are also shorter and more to the point, which is always good. After all, that's why you're summing it all up in two sentences, so it can be short and memorable. If the sentences are long and confusing it defeats their purpose.