U.N. Security Council Resolution 687 banned Iraq from possessing missiles with ranges of more than 150 kilometers (93 miles), and with good reason: Capable of carrying warheads of 2,000 pounds, Scuds can inflict massive damage. For years afterward, U.S. and U.N. spokesmen routinely described the Scuds as part of Iraq’s arsenal of “weapons of mass destruction.”

Now, for the first time since 1991, Scuds have been launched — by the Syrian government of Bashar al-Assad against its own people. On Wednesday, the New York Times quoted administration sources as saying that over the past week government forces had fired at least six of the Soviet-designed missiles from an air base north of Damascus at rebel-held ground in the north of the country.

The Obama administration’s reaction? None, so far. In fact, the administration has refused to publicly recognize that Scuds were used. State Department spokeswoman Victoria Nuland said Wednesday that “we have in recent days seen missiles deployed,” but she refused to comment on whether they were Scuds.

When we asked the White House whether the administration planned any specific response to the Scuds, we were referred to comments made this week in Morocco by Deputy Secretary of State William Burns, who said nothing about them.

These dodges are sadly understandable. President Obama remains determined not to intervene in the Syrian conflict or to provide arms to the rebels, regardless of the cost in lives (40,000 and counting) or the growing threat of the war to U.S. interests across the Middle East. It’s undoubtedly embarrassing for the administration to concede that even the use of Scud missiles will not draw a U.S. response.

Moreover, having declared that the use of chemical munitions would provoke “consequences” while otherwise ruling out intervention, the president signaled that every other weapon in the Syrian arsenal would be tolerated. The non-response to the past week’s attacks confirms such a conclusion and will likely encourage more strikes: The regime is believed to possess hundreds of the missiles. Meanwhile, the Lebanese militia Hezbollah, which reportedly acquired Scuds from Syria in 2010 for possible use against Israel, will likely draw its own lessons from Mr. Obama’s passivity.

Syria is reported to have chemical-weapon warheads that can be carried by Scuds. If there is a missile-borne chemical attack, will the United States be prepared to quickly respond, in order to prevent further atrocities? If so, Mr. Obama has given no public indication of it.