I suppose he could call for another crusade or maybe dispatch the Swiss Guard to the region. /S

Somewhat more seriously, though not something I'm actually suggesting or would necessarily want to see, he is a head of state and a prominent public figure, it wouldn't be out of the question for him to play a role in some sort of negotiations as an intermediary or something.

He also has the ears of potentially every Catholic in the world, as well as non-catholics who may want to hear his perspective, and while I'd personally very much rather the church mind their own business and not get involved, he could potentially give guidance to them about how they should feel about the situation, what they can/should or should not do to help, what they should be asking of their governments, etc.

Again, I personally would rather the church keep out of it, but those are some options available should people feel that the Pope should involve himself.