U.S., RUSSIA AGREE TO NEW NUCLEAR ARMS TREATY…. Breakthroughs like these do not come often.

Shortly after concluding a phone call with Russian President Dmitri Medvedev, President Obama made a surprise visit to the White House briefing room to hail the new arms control agreement with Russia, replacing the Strategic Arms Reduction Treaty (START) treaty that expired on December 5th.

“I’m pleased to announce that after a year of intense negotiations, the United States and Russia have agreed to the most comprehensive arms control agreement in nearly two decades,” the president said from the press podium.

Negotiations on the new START treaty with Russia have been worked on intensely for the past year. Mr. Obama said today it had been one of his highest priorities since taking office.

“It cuts — by about a third — the nuclear weapons that the United States and Russia will deploy,” Obama said describing the agreement. “It significantly reduces missiles and launchers. It puts in place a strong and effective verification regime. And it maintains the flexibility that we need to protect and advance our national security, and to guarantee our unwavering commitment to the security of our Allies.”

The treaty will still have to be ratified by the Senate, where it will need 67 votes. Administration officials emphasized this morning that they’ve been in frequent communication with lawmakers from both parties during the talks with Russia, and they’re confident of “strong, bipartisan” support for the agreement.

As for Medvedev needing approval from the Duma, Secretary of State Hillary Clinton offered to send Rahm Emanuel to Moscow to help whip up some votes. She was kidding. I think.

President Obama will reportedly sign the treaty in two weeks at an event in Prague.

As for the larger context of the Obama presidency, can you believe this week? A historic success on health care, a successful overhaul of federal student loan programs, and a new nuclear arms treaty with Russia — all in the span of four days?

I’m going to go out on a limb here and say that we won’t hear any more talk about the president “lacking accomplishments” for quite a while.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.