(CNN) -- When Russian Minister of Defense Sergei Shoigu stated that the Russian troops along Ukraine's borders were only conducting "training exercises" and have no "intention to cross Ukraine's borders or to engage in any aggressive actions," Ukrainians rolled their eyes. And when President Vladimir Putin told Ukrainians "Don't believe those who terrify you with Russia, who shout that other regions will follow Crimea. We do not want Ukraine's division. ... We want Ukraine to be a strong, sovereign, and self-sufficient state," Ukrainians shrugged. The problem is, even if Putin and Shoigu were being sincere, Moscow has lost all credibility among most Ukrainians and the international community. After three weeks of aggressive Russian behavior and the possibility of existential annihilation, Ukrainians, like Israelis, prefer to think in terms of worst-case scenarios. After all, they blithely assumed Russia would never attack -- and then Russia seized Crimea.
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Alexander Motyl: Ukrainians don't believe Russia's assurances it will not invade
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He says people are buying guns, leaving town, packing suitcases to be ready for war
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Motyl: Ukraine is beefing up its decimated defense; sending troops, tanks to borders
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Motyl: This may be Putin's worst strategic move, alienating other small, nearby nations
While Ukraine's security may or may not be enhanced by most of these measures, the irony is that @placeholder's definitely will not be -- at least in the medium to long term.