Interpreting the Islamic State’s jihadi logic

Interpreting the Islamic State’s jihadi logic - The Washington Post:
"What was the Islamic State thinking?


We know it is sophisticated in its use of modern media.
But what was the logic of propagating to the world videos of its beheadings of two Americans (and subsequently a Briton) — sure to inflame public opinion?

There are two possible explanations. 
One is that these terrorists are more depraved and less savvy than we think.
They so glory in blood that they could not resist making an international spectacle of their savagery — after all, they proudly broadcast their massacre of Shiite prisoners — and did not quite fathom how such a brazen, contemptuous slaughter of Americans would radically alter public opinion and risk bringing down upon them the furies of the U.S. Air Force.

The second theory is that they were fully aware of the inevitable consequence of their broadcast beheadings — and they intended the outcome. 
It was an easily sprung trap to provoke America into entering the Mesopotamian war.

Why?"