could my problem be weak abs?

About a year ago, I stopped doing direct ab work, figuring (like I've read a million times) abs get a ton of indirect work from almost every exercise. Now, combine this with the fact that I can't seem to do squats right. Could weak abs be my problem with squats?

Also, could weak abs be slowing/stopping my gains on other exercises? I WILL be starting direct ab work again no matter what (starting today), but I was just wondering, if it turns out that stopping direct work has given me weak abs, could it be screwing up my lifting as a whole?

Thanks in advance.