Why not? Because if we give the ISIL jihadis enough time, they'll put more human shields in the way to take advantage of our rules of engagement:
It is unlikely more American air strikes or talk about commando operations will make a difference and that is because the U.S. refuses to do anything about the very restrictive ROE (Rules of Engagement) used so far. ISIL has exploited this ROE by widely using human shields at many of its key bases. This recently led to ISIL putting hundreds of Shia into steel cages and moving them around by truck to where an air strike was anticipated. ISIL put pictures of these caged human shields and in general dared the United States to hit a target protected by caged Shia.
So we took our shot and did some damage.
But I assume that ISIL oil revenue will take a hit and then slowly climb as they adapt.
This is one way ISIL will adapt:
Now ISIL will have to hold hostage family members of drivers and execute hostages if drivers run away. This is an ancient technique that is still widely used in the Middle East.
But oil revenue is so important that I think it will include putting cages of captives in trailers towed behind the tankers. Keeping our bombs away rather than keeping drivers in the trucks is the higher priority.
