Military tensions between Syria and Turkey have risen dramatically in the last two days. After shooting down a Turkish fighter jet in June, Syrian government forces reportedly fired into Turkish territory and killed five civilians yesterday. Turkey has responded by shelling targets in Syria.

Though presently limited, the attacks are of keen interest to the United States. Turkey and the United States are both members of NATO and thus parties to the North Atlantic Treaty. Article 5 of that treaty establishes collective self-defense obligations by providing that in the event of an armed attack against any NATO member, every other member “will assist the [attacked member] by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain security of the North Atlantic area.” Thus, the Syrian attacks on Turkey might conceivably require the United States to come to Turkey’s defense.

That being said, it is doubtful that the United States will be involved in a defensive military action against Syria anytime soon. First, one would think that further escalation is unlikely. For Turkey, it would likely mean an even greater influx of refugees; for Syria, an international conflict could only hasten the downfall of the already crippled government. This is significant because NATO held an emergency meeting yesterday without invoking Article 5, and in doing so signaled that the current state of the conflict is insufficient to trigger collective defense obligations. Second, even if the conflict escalates and NATO invokes Article 5, the treaty would require the United States only to take “such action as it deems necessary” to restore and maintain security. That action does not necessarily include the use of military force; the particular form of assistance would be for the United States to decide in its discretion. Given the war-weariness of the American public and the Obama Administration’s decision not to intervene so far, the United States might try to fulfill its Article 5 obligations through means other than combat.