heheheh..."hard-on colliders."
Anyways, these are the three most plausible outcomes for me:
1) Zombie Outbreak. Between nanobots, re-animation, and mind-eroding parasites, science is well on its way to becoming the main consumer of human brains. Lax gun control ensures that we will be able to defend ourselves suitable well. That, and islands.
2) Nuclear Crisis. The vast majority of people wouldn't be able to afford shelter of any sort, so when North Korea can finally move on up from cardboard and the bones of its citizens as major building materials for missiles, or when Amadhy decides to get off his lazy ass and purge the world of Semites (that is, the whole Middle East), only the most protected and privileged will go on to advance the human race in a nuclear wasteland.
3) Galactic Expansion. The erosion of archaic ideals, prejudices, and beliefs allows humanity to enter a new Golden Age, where peace and prosperity reigns. Without war or stupid campaigns, we would be free to divert our resources to new enterprises, including planet mining, moon colonization, and further contact with aliens, which may or may not result in a short-lived military engagement. We get an embassy on the Citadel. You know the rest.