Clashes have erupted on the Greek-Turkish border, with Greek security forces using tear gas and a water cannon to hold back the thousands of migrants and refugees trying to enter Greece. Tear gas was also reportedly fired from the Turkish side of the border into Greece.

Over the past week, the situation on the border has been alarming, after Turkey declared that it had opened its borders with Europe, a move seen as Turkey’s attempt to force the EU and NATO to support his military operation in...