The fundamental issue, the most important issue should be fighting Islamic Terrorism.
Fighting Islamic Terrorism, like fighting a war on drugs, is ultimately unwinnable. Like illegal drugs, the fundamentalist ideology that creates terrorism will always have a receptive audience. No amount of education or appeasement can dissuade a segment of the population from wanting to use recreational drugs or embracing fundamentalist ideology.
Although it can't be eliminated, it can be contained. To do so would require a significant change in defensive policy and military doctrine from conquering countries that we deem threats to isolating those countries.
I don't mean isolation as in shunning them at the UN or imposing sanctions. I mean complete and total isolation from the world grid. No travel to or from. No international shipping to or from. No access to telecommunications networks or even mail. Full, complete isolation.
Drug cartels cannot exist without free (or easily bypassed) access to the market of new drug users. Fundamentalist ideologies cannot exist without similar access to a steady stream of willing acolytes. Removing that access means the suppliers wither and die within their containment zones.