Don't do it.
If your incoming flight is late, your flight to WAW (and whatever further from there, like a return) is gone, and unless it was a flex ticket, you're out of luck. 2 hours on 2 PNR is way too little. Even if you have maybe a 90% chance of making it, I wouldn't do it. 3 hours at the very least, and even then, only when the incoming flight historically run on time at 95%++
Certainly there must be connections with other airlines to WAW (if this is your final destination) giving you more time to connect in JFK, which I would chose, even if it means connecting again at another airport in Europe (ZRH, FRA, etc)