The US bombing of insignificant ISIS positions adds to delusion of their fighters and sympathisers that they are in war with the West, not created and finance by. It is more of a recruitment advertisement for anti-western Muslim young to join ISIS.
Secondly it is a strong message to the Kurds lest they forget the only real friend they have is US - friendship with Turkey doesn't save. Thirdly it is also an ultimatum to Turkey that further military decisions will be taken unilaterally by US and there is no need to even consult them. The kidnapped officers are their own problem.
Fourthly this bombing and recent disclosure of a Kuwaiti financier are messages to ISIS top rank that scenes on western media with non-Muslims is not acceptable and while they can crush any Kurd outside the zone, driving in the Kurdish autonomous region borders will not be allowed.
The artificial and genetically engineered caliphate is one of the cleverest recent projects of the West, and is likely to be the brainchild of the mysterious man in CIA in charge of the war on Islam, who is himself a self-declared convert to Islam. ISIS project is here to stay and can be inflated into a global Islamic state fully controlled by the West.
While Muslims of all creeds and lifestyles, from Bosnia, Turkey, Bangladesh, Nigeria, Egypt, Indonesia, Senegal or Uzbekistan, do not see that that the only way for them to survive is to cooperate, stick together and build a tolerant and moderate Islamic union similar to the EU, the men in charge of crushing them already see if that may become real and synthesise their own violent robot, call it the Islamic State, and destroy the Islamic world physically and spiritually from within.