It's been nearly twenty years since the last nuclear treaty between the United States and Russia. Proposed by President Reagan, the first START (STrategic Arms Reduction Treaty) dictated caps on deployed weapons that ultimately led to eliminating 80% of the nuclear weapons in existence. Today, a new agreement between the two nations was signed by Presidents Obama and Medvedev establishing new warhead restrictions that will ultimately eliminate another third of the arsenal. The agreement focuses heavily on definitions (ie a deployed bomber counts towards the warhead limit) and verification processes. Although the language alludes to the relationship of offensive and defensive capabilities, restrictions on defensive technologies was left out allowing the United States leeway for missile defense systems.