I'm not sure the "spreading cancer" analogy is useful from the start.

Cancer is a major threat to life, a potentially fatal disease. Al Qaeda specifically and Islamic extremism generally are not and never have been an existential threat to the US.

"Spreading" is substantially exaggerated IMO. These movements have not been eliminated but they haven't gained in influence or capacity either. In many areas (SE Asia was once melodramatically called the second front in the GWOT) they have declined.

I don't see any impending moment when there can be a "victory" over these movements; it's not that kind of fight. It will be a long fight, but that doesn't mean it has to be a long war. I don't think turning it into a war is advantageous to us.

If I had to outline a very general program, it would look something like this:

1. Defend effectively. Monitoring, tracking, infiltrating, and disrupting plots won't eliminate the antagonists, but it can minimize their impact, deprive them of high profile success, and isolate them from supporters who want to see results.

2. Attack effectively. Find and eliminate the key individuals on the operational and the funding/support side by whatever means work.

3. Starve them. Don't occupy territory, don't feed that "expel the infidel from the land of the faithful" narrative. Extended occupations of Muslim territory provide a discrete, specific target for jihadi propaganda and fundraising and should be avoided. We'll never convert the inner circle, they have to be killed, arrested, or driven so far underground that they can't operate. The inner circle can be isolated from their sources of support and recruitment.

4. Don't be stupid. There will always someone who will tell us that the cause of all the mess is bad governance in Muslim countries and we can fix the mess by fixing governance in Muslim countries. Trying to do that is just going to get us deeper in the $#!t. It can be argued (though often exaggerated) that the bad governance problem is to some extent something we helped create, but we can't undo the effect of meddling past by meddling again.

It's certainly a fight, but I don't think it has to be a war. Going big and heavy and indulging in excesses like regime change and nation building does not earn us any advantage and can be a real liability.

All IMO, obviously.