Ukraine’s unexpectedly stout resistance to Russian president Vladimir Putin’s war of aggression has contradicted many expert predictions and popular assumptions about Russian military performance and prowess. Faced with a protracted war of attrition instead of a rapid coup de main against the Ukrainian government, Putin has resorted to a controversial call-up of military reserves in order to replace lost manpower and blunt the momentum of Ukrainian counteroffensives supported by NATO weapons and intelligence.

Unfortunately, Putin has not stopped there. He has also issued repeated threats of nuclear first use against Ukrainian forces, especially those fighting in four eastern and southern regions, and, presumably, any conducting strikes into Russian state territory. Putin’s references to the possibility of nuclear use have been seconded by other officials in the Russian government, including former President Dmitri Medvedev, and widely broadcasted on Russian state media.

Some NATO military analysts might dismiss Putin’s references to nuclear first use as a bluff to compensate for Russia’s embarrassing military incompetence in conventional warfare. Prior to the war against Ukraine, Russia was widely regarded as the world’s second leading military power—not only on account of its large nuclear arsenal. Under Putin, Russia has rebuilt a good deal of the military capability lost during the lean years following the demise of the Soviet Union and the economic chaos of the 1990s. Russia’s military doctrine and organization for fighting modern conventional wars have also been revamped, especially since the reforms beginning in 2007. Russia has made great efforts to improve the quality of enlisted personnel and lower-ranking officers, as well as providing rhetorical commitments for recruiting and retaining more contract soldiers to rely less on draftees.

The war in Ukraine, however, has shown that many deficiencies remain in Russian military training, planning, command and control, logistics, and combat operations and tactics. Most notably, Russia has maintained the Soviet-style system of top-down command even for the most trivial decisions, discouraging initiative on the part of junior officers and senior enlisted personnel who might have more timely information about the conduct of battle. In contrast, Ukraine has developed a new generation of military leaders who are culturally adaptive and able to take the initiative and maximize their advantages in a fast-moving information environment. As a result, Ukraine has utilized a more fluid military structure that combines regular units with partisans and other volunteer forces to close the OODA loop (observe, orient, decide, act) faster than its Russian opponents can. NATO intelligence support, transfers of advanced weapons, training, and financial aid have also paid dividends for Ukrainian forces.