Vlad Putin and his boys are shaking in fear.I hope Lucianne.com is deliberately misunderstanding the role of that token force. Nobody suggests their role is to turn back the Russian Army's hundreds of thousands of troops.
The role of those 1000 armed Americans is clear. Like the U.S. troops in South Korea, our troops in Poland will be a well-advertised, highly visible tripwire.
If the Russian Army punches through them, killing many or most, the United States will almost certainly go to war with Russia. Which war is very likely to escalate into a nuclear exchange.
Presumably this is an eventuality Russia wishes to avoid. Thus the probability of a Russian attack on Poland is lessened.
NATO intends to station a modest number of troops in Latvia, Lithuania, and Estonia for the same reason. "Tripwire" forces lower the likelihood an attacked nation's "allies" can weasel out of coming to its defense, raising the perceived risk to an aggressor.