According to the most recent START Treaty exchange data, on January 1, 2007 Russia had 741 strategic delivery platforms that could carry up to 3281 nuclear warheads. The most significant development of the 2006 was deployment of three mobile Topol-M/SS-27 missiles. Russia also continued gradual decommissioning of older missiles – R-38MUTTH/SS-18, UR-100NUTTH/SS-19, and Topol/SS-25.