What a mess. As Turkish forces pour into northern Syria – for the first time in the six year civil war – things are just getting even more complicated.Following the Turkish contingent, hundreds of rebel fighters on Wednesday – trained and supported by the US and Turkey – entered the strategic town of Jarablus near the Euphrates River. The new invaders are also supported by US-led coalition air cover. The Turkish military operation coincides with the visit to Ankara by Vice President Joe Biden, who voiced support for Turkey and seeks to dispel any doubts about the United States’ solidarity with its NATO ally.The Syrian Foreign Ministry rushed to issue a statement condemning the Turkish invasion. But that statement seems like lip service to defend its sovereignty, while the Bashar Assad regime has no say in its own country. The Turkish military operation wouldn’t be possible without at least tacit approval by Russia, the guardian angel of the Assad regime. The Turkish move is a direct and immediate result of the reconciliation between Recep Tayyip Erdogan and Vladimir Putin. Still, for the record, Russia’s Foreign Ministry expressed concern about the invasion.Officially, the Turkish incursion is aimed against ISIS, which was in control of the invaded area. But Ankara has much more important and ambitious goals. Above all, it aims to curtail the advance of the Syrian Kurdish warriors, who are allies of the US and are trained by its special forces. Just a week or so ago, the US backed the Kurdish fighters in capturing from ISIS the town of Manbij, not far from Jarablus.Turkish officials said the operation is intended to warn the Kurds to move east of the Euphrates River, away from the Turkish border, and to prevent the creation of a Kurdish independent state or autonomous area in Syria, fearing it would inspire Turkish Kurds to have a state of their own.Now the US has to act as a juggler, maneuvering between the contradictory interests of its two allies in the war against ISIS, the Kurds and Turkey.It’s not difficult to assume Washington will prefer Turkey and once again betray the Kurds. The Turkish move signifies a U-turn in its policy. Since the start of the civil war in March 2010, Turkey has demanded the toppling of Bashar Assad and tacitly supported ISIS. It purchased oil from the terrorist group; allowed volunteers from all over the world to cross its territory to join the group and even armed them.For years it refused to bend to US pressure to stop its support for the terrorists, and looked with sympathetic indifference when ISIS barbarians brutalized and murdered Syrians especially the Kurds.Eventually Ankara found itself in conflict with its neighbors and its allies: the US, EU, Syria, Iran, Iraq and in recent months Russia and of course the Kurds, whom Ankara hates more than anyone else.Furthermore, the Turkish policy backfired. It found itself being targeted by both the Kurdish PKK guerrillas and ISIS terrorists, which turned Turkish cities into war zones.With Turkey’s failed coup d’état, Erdogan decided to change course.He reconciled with Russia (and for that matter Israel), declared war on ISIS, improved to a certain degree relations with the EU, tried to mend his differences with Iran and now after the invasion of Syria will most probably stop demanding regime change in Syria.The surprise Turkish operation further seals the fate of ISIS, which is losing more and more territory on the battlefield in both Syria and Iraq. In a few months, the Iraqi Army hopes to retake Mosul, the second largest city in the country.Yet while ISIS is on the verge of collapse, the Turkish invasion may prolong the war in Syria, with its labyrinth of global, regional and local conflicts and hatreds.