I can.
Preemptive action, will guarantee this scenario to be stifled before a massive loss of human life should even be considered.
Yes - preemptive action now may stop terrorism for the time being - but in the future you can be assured there will be other conflicts - and the WMD will be even more prevalent and accessible.
Which leads back to my initial premise. Planet earth will become either number 1 or number 2 (no pun intended).
Perhaps, that will postpone only the inevitable?