Let's face some harsh reality, folks. While we won World War II in the European Theater, infantry anti-tank weapons were not one of the big reasons why. The sad fact of the matter is that the M1 and M9 bazookas were…well...GlobalSecurity.org notes that they "could not penetrate the heavy front armor of the German tanks."
Suppose, though, that the GIs had perhaps the most modern anti-tank missile in the world. One that could reach out and touch the German tanks at a much safer range for the anti-tank specialists. In other words, imagine they had the FGM-148 Javelin. How might the Battle of the Bulge changed?
Let's look at the Javelin to understand how the battle would change. According to militaryfactory.com, the Javelin uses imaging infra-red guidance. By contrast, the bazooka rounds were unguided. This meant that the Javelin missiles have a much better chance of hitting their targets.
The Javelin also has longer range, a little over a mile and a half, compared to the bazooka's two-tenths of a mile, allowing the anti-tank teams to move out of the way — or reload.
But how would World War II GIs have used the Javelin? While some infantry units might have these missiles, it is far more likely that they would have been used for blocking and delaying the armored thrusts. The best vehicle for that purpose would have been the classic Jeep.
According to militaryfactory.com, this vehicle could carry a driver and four troops. Or, a two-man Javelin team and, say, six to eight of the 33-pound missiles and a 14-pound launch unit. A section of two vehicles could easily be expected to take out a company of German tanks.
Their most likely use would be in ambushes, using hit and run tactics to weaken German units and to buy time for reinforcements of heavy units (like Patton's Third Army) to prepare a devastating counter attack.
But its sheer effectiveness may even have ended that battle much sooner simply because the initial attacks would likely have been blunted — and the German tanks would have required infantry to move ahead to clear likely ambush sites, and that would have made it impossible to achieve the objective of capturing Antwerp.
That said, while tactically this alternate Battle of the Bulge would have been a quicker win for the Allies, strategically German resources might not have been depleted so badly. This would mean a longer war and potentially more casualties — and the first atomic bomb may have been dropped on a city in Germany, not Japan.