<a href="https://en.wikipedia.org/wiki/Cold_War" id="mwAWc" rel="mw:WikiLink" title="Cold War">Cold War</a>: The United States, the United Kingdom, and the Soviet Union sign the <a href="https://en.wikipedia.org/wiki/Partial_Nuclear_Test_Ban_Treaty" id="mwAWg" rel="mw:WikiLink" title="Partial Nuclear Test Ban Treaty">Partial Nuclear Test Ban Treaty</a>.