Several nations have been playing a role in the escalation of the Syrian Civil War, but none moreso than Turkey. They have hosted the Free Syrian Army, the largest of the rebel factions, have provided them international diplomatic access through their foreign ministry, and have loudly pressed for regime change in their favor.
But hindsight being 20/20, few nations have ended up worse off from this war than Turkey, which has seen its fears about Syrian Kurdistan exerting independence coming to pass and has been a huge swath of land along its southern border turn into a protracted battlefield.
The “Kurdish problem” was supposed to be the whole reason for Turkey’s intervention in the Syrian conflict, backing the Sunni Arab nationalist faction which was seen as hostile to Kurdish independence, but which is now struggling to assert itself in any permanent way.
Meanwhile Turkey has alienated its long-time ally, the Assad regime, and is also now in a major rift with Iran, which the Erdogan government had been trying to improve ties with for years.