Well, at this point in human history, the Gospel has a handful of global rivals. The two that come to mind are secular humanism, and Islam. It is within our power to "charge the gates of hell with a water pistol," to tackle both of those foes, through faith and obedience. For example, when we make sure our kids get a Christian education (at home or in a parent-controlled school), we starve the one beast of the fodder it most desperately yearns for -- the hearts, minds, and souls of our children. We can also get to know the Muslim students in our midst, "adopt" them into our hearts and lives, pray for them, and tell them about Jesus.
Getting back to your point, though -- if the "Sampson Option" happened, a billion of our fellow men would find themselves spiritually and emotionally devastated. Will we then have the credibility to offer Christ to them? Now is a good time to start learning Turkish, Farsi or Arabic, since those are long lead-time projects. I really believe, as the poem says,