Sigma I-62 war game
... that two and a half years before the Tonkin Gulf Incident, the Sigma I-62 war game concluded that American intervention in Vietnam would be unsuccessful?
... that two and a half years before the <a class="mw-redirect" href="./Tonkin_Gulf_Incident" id="mwBqc" rel="mw:WikiLink" title="Tonkin Gulf Incident">Tonkin Gulf Incident</a>, the <b id="mwBqg"><a href="./Sigma_I-62_war_game" id="mwBqk" rel="mw:WikiLink" title="Sigma I-62 war game">Sigma I-62 war game</a></b> concluded that American intervention in Vietnam would be unsuccessful?