In a somewhat surprising reversal, President Obama decided not to sign the 10-year extension of the Iran Sanctions Act passed by Congress, as he had been expected to do. Instead, the ISA extension will become law without his signature.

The White House has repeatedly stated it does not believe extending the Iran Sanctions Act violates the nuclear deal, and said so again on Thursday: “This Administration has made clear that an extension of the Iran Sanctions Act, while unnecessary, is entirely consistent with our commitments in the Joint Comprehensive Plan of Action (JCPOA). Consistent with this longstanding position, the extension of the Iran Sanctions Act is becoming law without the President’s signature.”

Iran, of course, vehemently disagrees, and has threatened retaliation for the ISA extension.

The Washington Post notes this marks the first time in Obama’s presidency that he has allowed a bill to become law without his signature. The Post takes this as a “symbolic attempt to distance the president from lawmakers’ fresh slap at Tehran.”

House Foreign Affairs Committee Chairman Ed Royce (R-CA) sounded like he was in a slapping mood. “Don’t be fooled by Tehran’s rhetoric. Iran is the only party that has broken terms of the deal,” he said, stressing that extension of the ISA “ensures the Trump administration can ‘snap-back’ other powerful sanctions when the ayatollah makes a rush for a nuclear weapon.”

One of the major points of contention between the White House and Congress, a bipartisan majority in Congress at that, has been whether the ISA must be kept alive to make “snap-back” possible. Although the Obama administration has long said it’s not necessary, the Post notes that today the administration “stressed that Iran would be unaffected by the renewal, as long as it continues honoring the nuclear deal” – which sounds like a tacit concession that extending the Iran Sanctions act does make a difference, if Iran commits further violations of the JCPOA.