During the 2008 presidential campaign, Barack Obama emphasized the importance of preventing nuclear terrorism by saying that he would hold a summit in 2009 — his first year in office — "and regularly thereafter."

In 2009, we rated this promise a Compromise because the first summit was scheduled to take place a year later than Obama had pledged. But since then, summits have been held in both 2010 and 2012, and we have decided to change our rating.

The first conference was held in Washington on April 12 and 13, 2010. The second was held in Seoul, South Korea, on March 26 and 27, 2012.

Not all nuclear arms-control advocates were satisfied with the outcome of the 2012 conclave -- the editors of the Bulletin of the Atomic Scientists had a somewhat pessimistic assessment -- but more directly relevant to Obama's promise, the meetings have become institutionalized on a once-every-two-years basis, including a 2014 summit scheduled to be held in the Netherlands.

Matthew Bunn, an associate professor of public policy at Harvard University's Kennedy School of Government, says the one-year delay is less significant than the fact that two summits have been held and a third has been scheduled. We rate this a Promise Kept.