The most important move is allowing the Americans access to the Turkish air base at Incirlik. This immediately allows the US to step up its air strikes in both Syria and Iraq. Its jets can get to targets more quickly than from the Gulf, they can stay longer, they can carry more firepower. This increased ability will in turn put pressure on the White House to sanction sending US forward air controllers into the battle zones to help pinpoint targets. The use of other bases cannot be ruled out.
The second move intersects with the first. Turkey has moved a huge number of troops right up to the border with Syria along a long section of territory. After years of turning a blind eye to Islamic State fighters transiting the region, Ankara has now moved to block them. That, added to the increased air power will reduce the supply of fighters at the same time as they will need re-enforcements due to the increased fatality rate they will suffer inside Syria and Iraq.
A secondary consequence of this will be a reduced ability to supply fighters with arms and money.
Partially provoked by increased ISIS activity inside Turkey Ankara has moved against the group’s network there arresting almost 250 suspects in raids across the country. ISIS has engaged in a classic case of overreach and the tide looks as if it has now turned against the group.
Turkish F-16s this week hit three ISIS targets inside Syria, and Turkish ground forces engaged in a firefight across the border.
Turkey now has a range of options. The details of the agreement with the Americans are not clear, but, according to some Turkish media reporting, may include establishing a buffer zone 30 miles deep inside Syria along a 50 mile stretch of border. If that happens it would establish a safe zone for anti Assad and anti ISIS forces to train and resupply as well as giving civilians respite from the fighting. If such a zone were created it would require a no fly zone above it. The latter could be established even if Turkish troops do not cross the border.
However, even if neither come to pass, Turkey’s moves will have seriously alarmed both Assad and ISIS. The latter knows that it will soon be coming under even greater pressure across the region. The gains of the last year have been halted, in some cases reversed, and that it likely to continue. With ISIS at least contained, the other rebel groups, now being trained and supplied in greater numbers, can coalesce and concentrate on fighting Syrian government forces. That in turn will put pressure on Assad to negotiate a way out, or fight to the death.
Turkey was content to let ISIS flourish in the hope it would overthrow Assad, but with ISIS destabilizing Turkey it has, at last, acted.
The danger to Turkey now is that, with ISIS and Assad under so much pressure, the Kurds will continue to gain territory. To a great extent the Kurds rely on the American for support and it is likely that Ankara will have extracted a promise from Washington that the Americans will press the Kurds not to push for statehood. Any moves towards that risks further destabilizing Turkey, Syria, Iraq, and Iran, all of which have significant Kurdish minorities.
It is no co-incidence that two days after the Incirlik base agreement was confirmed the US Defense Secretary, Ash Carter, turned up on an unannounced visit to Irbil – the capital of Iraqi Kurdistan