War is just police violence outside of the belligerents' own borders, and it's been said by many(and readily observable) that foreign wars are essentially training for domestic tyranny. UAVs go overseas, a few decades later they come home. Extrajudicial(due-process-free) targeted killing of citizens in foreign countries? Now it's kosher here. Excuse this kind of action in the name of officer safety or whatever you want to call it, but like it or not they got away with it here so you can expect to see it a lot more in the future.
Regarding the "weapons of war" distinction, I firmly believe that such a label is misleading and inappropriate. There are no weapons of war and no weapons of peace, only weapons of differing scale. As weapons increase in effect, their use becomes more and more difficult to morally justify as defensive. Explosives are a step up in scale, which is probably one reason many here would have a problem with cops using them.
The other factor which should make you itch is the removal of personal risk to cops. We have seen over and over that making things safer for police inevitably results in more widespread use. SWAT teams with huge budgets, serious weapons, tanks etc reduce cops' risk of bodily harm. 80,000 raids a year and climbing, for ever-smaller "crimes". Sovereign and qualified immunity, jury-stacking and judicial collusion and a sycophantic media and public insulate against legal and financial responsibility. Cops now are trained to act more aggressively(often first in the military, then in the academy) and now can pretty much kill at will without fear of any liability - and they are agitating for MORE protection(restrictions on releasing the names of cops who kill, police bills of rights, etc).
This even shows up in the mundane: photo radar and red-light cameras are free money for departments and cities, so they find their way into more and more places - and they're often not predatory enough to suit the moochers: stories abound of cities shortening yellow-light intervals in order to increase "violations".
Remember the video of the cop breaking the autistic kid's arm to get him off the schoolbus when he wouldn't stop screaming? How about the cop who responded to a backup call for help restraining a guy who was siezing or having some sort of mental brrakdown, said "I don't have time for this" and fatally shot him in the chest? I don't see this as essentially different(although I understand that the Dallas shooter was competent and armed). It's violence as a measure of expedience, not a last resort. If you're not willing to assume some risk as a cop, either go home and apply for a real job or have the honesty to drop the hard-ass supercitizen attitude. Policing SHOULD be dangerous.
Give this a pass in Dallas, and you invite it into your city.