Unfortunately we fall into the trap of guarding against the last attack. ( taking shoes off at TSA checkpoints for decades). Most likely the most idiotic security measure to make us feel secure.
We in America don’t want to be called names

(Racists, Xenophobes) So who ever wants access to our country is pretty much allowed in. Who knows what came in during Biden’s disastrous 4 years.
So it won’t be planes flying into buildings, but a plague on corn crops, soy beans, another more virulent strain of disease. An EMP pulse. Then maybe we wake up and no longer be concerned with being called names.
So unfortunately, it’s going to have to happen before we wake up. All you can do is be prepared for yourself.
Post script: China and other bad actors learned a valuable lesson from Covid that there were no consequences. If there is no Nation State directly linked. ( no one to bomb) lowers the deterrent.