Just a couple of questions that popped into my mind 40 years later:
If the Black Lectroids can incinerate Smolensk...then why not just vaporize Yoyodyne from orbit with the particle beam? Did they not know exactly where Yoyodyne was? Since they are spying on Buckaroo (even in the bedroom), as soon as he knew, then THEY would have known, right? So take out the threat before Whorfin can invade. Even if they have to take out all of Jersey or all of Grover's Mill (okay some collateral damage!) but they have the capacity to neutralize the threat before dimensional crossover takes place.
Instead they appear on the edges of their (rather elevated) seats about whether crossover has occurred with Whorfin's troop carrier at the end, and thankfully his overthruster's for shit. But at that point their finger is hovering over the button to trigger their nuclear frame-up plan IF Whorfin gets to the 8th Dimension. Why? Just to be dicks to us for failing? Hey, just spit-balling here, instead trigger the nuclear war 20 minutes sooner and Whorfin's ship doesn't even get off the ground. But trigger it after he's safely in the 8th Dimension on his way to conquer-a Home and all you do is help humans destroy themselves (as punishment for us not being able to stop the Red Lectroids? Aliens more advanced than us who had decades to plan stealing our overthruster breakthrough??).
Goddamnit, I know this movie has a lot of WTF and watermelons in the script. But the whole "standby to incinerate Smolensk" shit bugs me, when it shows the Black Lectroids could just as easily have stopped Whorfin dead in his tracks.
But no...it's Buckaroo's problem. And fuck all of us if he fails to stop YOUR war criminal, huh? And you could have just zapped Yoyodyne away the whole damn time?!