<a href="https://en.wikipedia.org/wiki/Operation_Igloo_White" id="mw5w" rel="mw:WikiLink" title="Operation Igloo White">Operation Igloo White</a>, a US electronic surveillance system to stop <a href="https://en.wikipedia.org/wiki/People's_Army_of_Vietnam" id="mw6A" rel="mw:WikiLink" title="People's Army of Vietnam">communist infiltration</a> into <a href="https://en.wikipedia.org/wiki/South_Vietnam" id="mw6Q" rel="mw:WikiLink" title="South Vietnam">South Vietnam</a> begins installation.