If your wife never had the habit of arguing with you, then its okay. But what if she stopped arguing with you only now? Does that mean anything?
Well, it could be a good thing. But wait, it could also indicate something else. Stoic silence could mean disagreement also.
If that is the case, it is better to argue for some time and solve the issue instead of maintaining silence for days or weeks. That will make matters worse.
So, here are some reasons why she stopped arguing with you.
She realised that you can't get her point. Maybe, she perceives you like a dumbo who can't understand her point. If that is the case, you may need to listen more and talk less.
She is planning to move on. If she has some secret plans of breaking up with you, obviously she doesn't want to pick any fights while going out. So, she must have stopped arguing with you.
She has grown up over the years. This could be a good reason. With each passing year, when your maturity levels increase, you tend to stop arguing and start understanding each other which is a good thing.
She doesn't want any more friction. Women who are vexed up with daily quarrels may choose not to argue any more. But that doesn't mean that they agree with everything. They just stop disagreeing vocally but it is better to be aware of their needs.
She is trying to adjust to your personality. This could be one reason. When a woman tries to adapt herself to the man, she may slowly mould herself up to his mind set.