Just before Christmas, the U.S. Senate ratified the START treaty with Russia that contained preambular language linking offensive missile reductions to U.S. limits on new defensive missile systems. It ratified the text based on President Obama's assurance that such language was not binding.
Now an indignant Russian Duma is promising to pass a resolution affirming that Russia does indeed consider the preambular language to be legally binding. The Duma would ratify the START treaty, along with any related statements and reservations, in February.
If that happens, there should be some red faces in Washington (I say 'should' because shame is an outmoded and fast-disappearing emotion). The great display of domestic bipartisanship and 'resetting' U.S.-Russian relations achieved by ratifying the START treaty will look like a farce. I have to imagine that the State Department and White House are scrambling to control the damage.