My guess is if there is at least one soul in the city that doesn't reject you, then you have your foot in the door at least - Green light. And there are at least 60 of these folks there, so..
Your (right-wingin_It's) answer sounds a bit like Lot arguing with God about 10 good people in Sodom, but OK, how about countries like Iran? Or Saudi Arabia? Pakistan? Cities like Fallujah? Or Mecca?
I have another idea - and it's just an idea - how about putting our (God's) resources where they can generate the most effective return (I hate using a financial term when talking about people but I don't know how else to phrase it).
Just to pull a nation out of a hat, and one that almost no one is familiar with, let's try Macedonia. It's currently about 33% Christian and 17% Muslim accoring to http://www.cia.gov/cia/publications/factbook/geos/mk.html#People
It's a country bordering Serbia, Bulgaria, and Greece, so it's right in there with a lot of other Christian/Muslim nations that stand a good chance of falling into the Islamic corner - like Turkey. If you were fighting a war (and we are, both spiritually and literally) would you send your warriors to a locale that's 99.8% enemy occupied, or would you reinforce a sustainable area? Easy question, right?
Then maybe later, we could work from an established base, and if we're successful in establishing democracy in a(n) Arab Country(ies), then (I believe) we'd be working in a less hostile environment (freedom!).
I still can't reconcile "dust off your sandals" with "go into all the world". Any answer I come up with seems to ignore one or the other. As a man, I lean strongly toward shepherding my resources where I can make them count. As a Christian, I simply don't know the answer.