The 21-year-old decided to leave White Hart Lane, and a club challenging for Champions League football, to join a newly promoted Cardiff side widely tipped for a season-long battle against relegation.
The acquisition of the England cap for an £8million fee was considered a great deal for the Bluebirds, but some were surprised at Caulker's decision.
The former Swansea man hopes the move will enhance his chances of being part of Roy Hodgson's squad for next summer's World Cup, and a strong performance against the likes of Sergio Aguero and Alvaro Negredo at Cardiff City Stadium on Sunday would not go unnoticed.
He said: "A good performance would certainly help me. It is always the aim to be part of the England squad and especially in a World Cup year. I am striving to get in that squad.
"But they have a lot of good players in that position and Roy Hodgson can only pick four centre-halves for his squad.
"Obviously, I am competing with the best in England but I will just keep working, focusing on my own game and if that call comes then great.
"My number one priority is to keep Cardiff in the Premier League, and with this game being on TV it's a massive opportunity.
"I want to bring my Premier League experience to this team and add that leadership to my game. I am only young but I want to develop that and be more vocal during games,
"It's more of a challenge here than it would be at Spurs - especially when you see them adding to their squad.
"I feel like it's a fresh challenge and one I am looking forward to, and I believe I can come through, along with the rest of the team."
Tottenham have spent heavily during the summer and, despite Gareth Bale's apparently impending departure to Real Madrid, they look set to be among the challengers at the top of the table.
But Caulker has no doubt he made the right move.
"I knew what I was coming here for and I am not looking back. I wish Tottenham well," he said.
"I understand why people question why I have dropped down. But people who knew me know I want to play football and challenge myself every week. I am young and want to play and get as much experience as I can.
"Tottenham is a club that has not produced a player since Ledley King, so it was slightly difficult to see your future there as a youngster."