The heading should give you a clue that the following is just a rambling, because trying to get a handle on the situation that is currently happening in Iraq and Syria is far too complex to put in a few paragraphs.
Currently the West is putting pressure on Turkey to get stuck in, as it's powerful army is just sitting on the Syrian / Turkish border watching what happens. The Turkish Foreign Minister has said that it is not practical for Turkey to get stuck in.
Two reasons for this are they are not happy helping the Kurds because of past history and Assad's biggest enemy at present is the Islamic State, tricky!
Apparently there are now over fifty countries involved in this dispute / war, so good luck getting that lot to agree to anything...