Kolo Toure believes he had to leave Emirates Stadium for Manchester City because Arsenal had lost too many influential players in recent seasons.
Ivory Coast defender Toure completed his move to City during the week and follows Emmanuel Adebayor in quitting the Gunners for Mark Hughes' side.
Arsenal have also sold the likes of Patrick Vieira and Thierry Henry over the past few years and Toure feels it was the right time for him to move on.
The 28-year-old said: "I came to Man City because when you look at Arsenal you see all the great players have left the club and are now in the past.
"Look at what has happened there. Thierry Henry has gone, Patrick Vieira has gone, Ray Parlour has gone.
"These were the players that brought success to Arsenal and I believed it was right at this stage of my career to also move on.
"We lost too many leaders at Arsenal. When we were winning the league title the spirit was fantastic, we were like a band of brothers."
Toure also defended City's spending policy, which has seen them criticised in some quarters for distorting the market.
"The best teams are at the top only because they have the best players and to get those players you have to spend a lot of money," he said.
"You can't be successful in football without money. This is the football business. City have a project to build a big team and so it is natural it is going to cost money."