Why Russia and Ukraine can't stop each other's air attacksRussia and Ukraine are both striking farther into each other's territory, and neither side has a good way to stop the attacks. Air offenses far outstrip air defenses, and there is no sign this huge gap will be closed anytime soon. Now, you hear the sirens - and you hear them most nights - you know Ukraine is out of the U.S.-made Patriot air defense missiles and is really helpless to stop these incoming Russian ballistic missiles. And Ukraine has run out of defensive missiles just as Russia is ramping up its production of offensive missiles. SUMMERS: And, Charles, lastly, this rapid evolution in the air war seems to be in contrast to the ground war that is largely a stalemate.