The Gunners are currently top of the Premier League by four points, and Wenger thinks that his side are stronger defensively than they have been over the past few years.
"What is different this season? Solidarity," Wenger told ITV Sport.
"When we have our backs to the wall, we can respond. We've lacked that kind of experience of winning the odd game when we haven't played well.
"That defensive stability is there for all to see [now]."
The Gunners host Marseille in the Champions League this evening.