Redknapp told The Sun: "Kevin loves Newcastle and Newcastle loves him. I originally said Alan Shearer was the best man for the job but that was only because - along with everyone else - I didn't think Kevin was in the equation.
"Yes, I know he had his problems with England and then got a little disillusioned with the game at Manchester City. But that probably stemmed from his enormous love for Newcastle.
"He felt so good and so comfortable for so long up on Tyneside that everything else - yes, even the England job - could never match it. He could never quite get the same enthusiasm for anything else.
"And that's why he's going back. Because there's nowhere else where he can get the same buzz and feeling for the game."
It's always said in football that you should never go back.
Yet Redknapp said: "Well, I went back to Portsmouth. People told me I was mad, that I had to be stark raving bonkers to return after all the bad feeling when I left the club.
"Portsmouth were near the bottom of the table and I was on a hiding to nothing. And so were the club. But look how that's worked out. Never go back? Well, I think I've blown that theory out of the water. And I think Kevin will do the same. He's bubbly and his enthusiasm will rub off on everyone at the club.
"He'll get among the players as well. There are more than enough decent professionals there for him to make a right go of it.
"I'm sad about what happened to Sam Allardyce but the situation now is that Newcastle need someone to kick-start it all again. And Kevin is the perfect choice.
"His time out of the game will have done him the world of good. He will be pumped up and confident that he can work the old magic again. If he wasn't, he wouldn't be going back.
"It's not only an appointment that will delight the fans but it's a tremendous coup for owner Mike Ashley. A lot of people were wondering just where Newcastle were going - and now's he come up with this. What a way out of the problem! Mike has put his money where his mouth is and I'm sure he will eventually get the success he deserves at the club. Kevin will get his 100 per cent backing and they will work really well as a team.
"It's a wonderful opportunity for Kevin but, at the same time, there will be enormous differences from when he was first there.
"The big question now is: Where the hell do you find decent players? He will want to play the old attacking football they love up at St James' but where do you find the likes of Alan Shearer, David Ginola, Peter Beardsley Andy Cole and Les Ferdinand these days?
"But if anyone can do it, Kevin can. The Geordie fans deserve success and now they have the man they want. Personally, it's great to see him back because he's so good for the game. But I'll tell you one thing - he won't be going anywhere after this. This will be the last job. There's nowhere left for him now."