U.S. suggests Putin's "peacekeepers" won't trigger "massive" invasion sanctions

A senior U.S. official told reporters on Monday evening Russia's plan to send "peacekeeping" forces into eastern Ukraine would "not be a new step," but it would make Russia's existing presence in the separatist-held areas "more overt."

Why it matters: The U.S. and its European allies have been warning for weeks that a Russian invasion of Ukraine would trigger "massive" sanctions on Russia. But they have not offered a clear definition of what would constitute such an invasion, and the senior official declined to do so on Monday's call.

Driving the news: Russian President Vladimir Putin announced in a combative, hourlong address on Monday that he would recognize the sovereignty of the Donetsk People's Republic (DNR) and the Luhansk People's Republic (LNR), which have been battling Ukrainian forces since 2014.

• The Kremlin then announced a "peacekeeping" mission to the two "republics," and the Interfax news agency quickly reported that armored vehicles appeared to be heading to Russia's border with the DNR.
• The separatists don't hold all of the territory they claim so recognition could swiftly evolve into war unless Russia limits its operations to the separatist-held areas.
• The U.S. responded with sanctions on the two separatist republics, and the senior official said the U.S. would issue more sanctions on Tuesday, adding that those were "not the swift and severe economic measures we've been preparing in coordination with allies and partners should Russia further invade Ukraine."

That led to a back-and-forth between the senior official and reporters on Monday's briefing call about what would constitute a "further invasion," and why Russia sending troops to the DNR and LNR would not meet that threshold.

• "Russian troops moving into the Donbas would not in itself be a new step," the official said. "Russia has had forces in the Donbas region for the past eight years," despite denials from the Kremlin, and "they are apparently now making the decision to do this in a more overt and open way."

Flashback: President Biden was criticized last month for suggesting that while the U.S. and Europe would be united in responding to a full-scale invasion, that might not be the case in the event of a "minor incursion." The U.S. and its allies have since gone to great lengths to signal unity and resolve.

What to watch: The senior administration official said the U.S. believes Russia has "plans for an invasion at any moment, most likely in response to attacks Russia falsely claims are occurring in the Donbas," and that such an invasion could go far beyond the separatist-held territories.

• If so, the U.S. and its European partners will have to determine what exactly would trigger the full package of sanctions.