Eli Lake, Bloomberg (USA)
The INF treaty was supposed to eliminate all missiles with a range of about 300 to 3,500 miles. When Reagan and Soviet leader Mikhail Gorbachev signed that agreement in 1987, they ended a dangerous standoff in Europe, where both sides had deployed hundreds of nuclear-tipped weapons. For 21 years, it worked. The U.S. stopped producing intermediate-range missiles, and so did the Russians. But in 2008, the same year Russia invaded Georgia, Moscow began to cheat.