Give us time, comrade.
There is no way to prevent such attacks, although they can be reduced in frequency. Even if all their nukes are intercepted and they are denied further use of airliners, they can still make smaller attacks like they do in Indonesia, Israel, India, and Philippines [the list goes on.] Even on full national alert it is not possible to watch everyone at all times. Of course everyone could be confined to their houses forever and your papers checked 14 times a day if starving everyone to death is an option.
Give us time, comrade.