How quickly could the quarantine on cuban have turned in to ww111

Rather easily actually. One wrong move and the Soviets could’ve launched their missiles. And of course the US would’ve retaliated just as quickly. It was a very tense situation

If the Soviet Union had elected to run the quarantine, the US would have fired on Soviet Ships. This would been an act of war, and the USSR would have no choice but to respond. This would have dragged in both sides allies, triggering a new world war. And an escalation to a nuclear exchange would almost certainly have occurred, as whichever side was losing in a conventional war would have had little choice but use nukes or surrender.