The six individuals who have been at the helm of the terror group are from Iraq
© Al ArabiyaThe six individuals who have been at the helm of the terror group are from Iraq.
A contrasting juxtaposition in my twitter feed:

First the U.S. Central Command tweet with this statement by the commander of the U.S. Forces in Afghanistan, General Nicholson:
GENERAL NICHOLSON STATEMENT ON THE KILLING OF THE THIRD ISIS-K EMIR BY U.S. AND AFGHAN FORCES IN THE LAST 12 MONTHS
...
"This operation is another success in our campaign to defeat ISIS-K in Afghanistan in 2017," said Nicholson. "Abu Sayed is the third ISIS-K emir we have killed in the last year and we will continue until they are annihilated. There is no safe haven for ISIS-K in Afghanistan." [bold added]
Then the Micah Zenko tweet with this interview with the commander of U.S. Central Command, General Votel. Votel is the direct superior of the above Nicholson:
Q: ISIS leader Abu Bakr Al-Baghdadi — dead or alive? And does it matter anymore?

Votel: [..] I hope that he is (dead), frankly. [..] That said, we've been doing this long enough to know that leaders are killed and we've killed plenty of them. And that there's always somebody who is going to step up into those positions so we shouldn't think that just killing Baghdadi is the key here. He can be replaced. So in that regard, it may not matter as much. [bold added]
Nicholson says he can win the war against XYZ by killing a bunch of successive XYZ "leaders". Votel rightly says that this is clearly not so. During sixteen years of War of Terror and constant killing of various "emirs" special boilerplate statements were prepared for the typical "victory" announcements. Votel seems to have understood that such killings do not matter. His direct subordinate Nicholson did not. Shouldn't they talk to each other about such issues?

But it may well be that Votel would have sounded very different if his troops had killed Baghdadi and not a Russian(!) air strike.