Louis van Gaal branded Manchester United “mean and low” and turned down the Belgium job so they had to keep paying up his contract.
Van Gaal, sacked by United after winning the FA Cup in 2016, was offered the Belgium job before former Everton boss Roberto Martinez was eventually handed it.
But Van Gaal revealed he turned down the chance to take them to the World Cup out of spite towards United, so they would have to continue paying up his contract after terminating it a year early.
“It would have been really great if I had become Belgium national coach,” said Van Gaal.
“But I was so resentful and vindictive that I let that job go by.
“It was stupid, really, because the sporting value should always come in the first place.
“That should have been the most important thing. But that’s how I looked at things.
“It was not about money. It was all about the act of revenge. I went for my instinct, not the rational. I just have to live with that. I’ve been a really successful manager, so I don’t want to slag the world of football down. I have had a lot of good times.’’
“But the way Manchester United have treated me was terrible. They have been mean and low.’’
Van Gaal accused United executive vice-chairman Ed Woodward of not being straight with him and going behind his back by lining up Jose Mourinho as his successor.
“In contrast, the way president Nunez of Barcelona treated me [when Van Gaal left] was fantastic,” said the Dutchman. “That proves that the world of football is not full of false people. There are also straight and warm people among those people.”
Van Gaal also claimed there was a deliberately orchestrated campaign to drive him out of United, with former players lining up to denigrate his style of play.
“The former players of United started to have a go, saying that I was giving the fans boring football,” said Van Gaal. “That struck me. It was directed, organised.
“After a while I started to think I’m losing my authority this way towards the players. So I had to make concessions in my approach of the players.
“That was tough, because I’ve always had my own way of coaching.’’
When he left United Van Gaal announced his retirement, but says he can see himself coming out of that soon. “I can see my self doing that, yes. But I could not take any job, because of the conditions Manchester United had put into my contract over my fee.’’
Van Gaal says he normally doesn’t talk about football at home with his wife Truus but at United he just couldn’t avoid the subject.
“Truus was the one who saw it all develop in the wrong way at United. She warned me six months before there was something going on, she could see it with the guys in charge of the club. Female intuition. For me that was a catalyst to get angry, because I was lacking that feeling. I did not see it coming.’’