The loss has been slammed by pundits who have criticised the third-placed Gunners for lacking the mental strength and hunger required to win the Premier League title.
Ander Herrera then fired United 3-1 ahead on 65 minutes prior to Mesut Ozil's strike less than fives minutes later and although the damage had been done, it was a performance which Wenger felt was decent despite the negativity his side has attracted.
"When we were on top of the game we conceded two quick goals from crosses," Wenger told Sky Sports.
"Overall, I think we had the first chance, we had a lot of the ball and we were caught on two crosses in the first half and in the second half on the counter-attack because we went after the game.
"They've scored the goals, we have to look at ourselves. What is for sure, our spirit and commitment was 100 per cent there but it is difficult to win away from home when you concede three goals.
"They stopped us a lot with little fouls and that was very frustrating, apart from that I could not question our desire or commitment at all."