Ahead of the tournament, both sides agreed terms on a four-year renewal, as Clarke led the Tartan Army to their third competition under him
However, the former Chelsea coach admitted he needed to push his case with the Scottish FA as he felt the governing body were waiting to see the outcome of the World Cup.
The 63-year-old insisted he always planned to resign if he failed to lead Scotland beyond the group stage for the first time as part of an explosive interview with former Chelsea and Scotland teammate Pat Nevin.
"It was never really a change of mind.
"I'm quite a complex person. I wanted to control my narrative.
"Obviously we got to March and I hadn't been offered a new contract, which I thought was pretty strange. You start to think are they hedging their bets a little bit, waiting on the tournament in the summer.
"So I did a little bit in the media in March to give the SFA a little shove. We negotiated non stop from the beginning of April to the middle of May, just before the Curacao game.
"And I said to them if we don't agree a new contract before the World Cup then I'll say I am leaving the job. They panicked a little bit and gave me the new contract.
"But I always knew in my head that if we did not get out of the group stage then I'd probably leave. The only way I would have stayed on is if they had been three fantastic games and they went against you."