In the Wall Street Journal today, four wise men of the U.S. foreign-policy establishment, George Shultz, William Perry, Henry Kissinger and Sam Nunn, have an op-ed about nuclear-weapons issues. This group, sometimes known as the "four horsemen" or the "quartet" since their landmark January 2007 Journal piece setting "the goal of a world free of nuclear weapons," now warns that "the pace of nonproliferation work today doesn't match the urgency of the threat."

This time, they focus on four specific areas where immediate actions might be especially useful. These are: 1) securing nuclear materials to prevent nuclear terrorism, through an aggressive recommitment to the Nuclear Security Summit process, 2) working with Russia to "take a percentage of" both nations' "nuclear weapons off prompt-launch status," 3) further reductions in U.S. and Russian nuclear stockpiles beyond those mandated by the New START agreement, both in strategic and tactical weapons, and 4) further work on verification and transparency.

These are all sensible recommendations, whether or not you happen to agree with their broader goal of a nuclear-free world. The first one is particularly unobjectionable given that, as Stephen Walt put it in 2010, nuclear-material security "is one of those (rare?) policy problems that we actually do know how to address." Even if one believes that the threat of nuclear terrorism has been overstated, there are hardly any convincing positive arguments for why we should want any of the world's nuclear-material stockpiles to be unguarded.

What is most noticeable about the quartet's proposals this time, however, is that they are carefully calibrated to political reality. In particular, they appear specifically designed to avoid requiring any action by the U.S. legislative branch. For example, in their third point, they state that in seeking to go "below New Start levels of warheads and launchers," Washington should explore "the possibility of coordinated mutual actions." This would be in contrast to a new treaty with Russia, which would necessarily require the consent of two-thirds of the Senate. Likewise, this piece does not mention the Comprehensive Test Ban Treaty, which would ban all nuclear tests worldwide and which the United States has not ratified. The four horsemen's 2007 op-ed encouraged Washington to initiate "a bipartisan process . . . to achieve ratification of the Comprehensive Test Ban Treaty," and President Obama promised to "immediately and aggressively" pursue its ratification in his 2009 speech in Prague.

This should not be surprising. The 2010 debate over New START was a difficult and bruising one, and Republican leaders have made it clear that there is little to no appetite for further nuclear reductions in their party. So while the four horsemen reiterate their support for global abolition in today's op-ed, their focus is really on building the space for what is politically possible in the immediate future, trying to recapture some of the momentum on nuclear issues from Obama's first two years in office without provoking any high-profile conflicts with Republicans. It's an approach that seems to more or less track with the administration's current thinking as well.