One little publicized aspect of the war in eastern Ukraine against Russian-backed rebels is the inefficiency of the Ukrainian military leadership. The most outspoken Ukrainian critics have been the few thousand Ukrainian special operations troops (commandos). These men are better trained and more experienced than most in the Ukrainian military and know a lot more about Western military practices. The main complaint is that the senior leadership are still stuck in a rigid mindset that was inherited from the Soviet era military. These attitudes were allowed to persist because the government and the military leadership believed they had no immediate military threat to deal with. That was because of a 1990s deal whereby Ukraine agreed to give up the Soviet nukes it inherited in return for cash and a promise from Russia that Russia would never take advantage of the surrendered Ukrainian nukes to try and regain control of Ukraine. A decade later Russia ignored that deal and grabbed the Crimean Peninsula in 2014 and is trying to grab more Ukrainian territory (the Donbas). Ukrainian military leaders were woefully unprepared for this.
Yet this Russian aggression was not entirely unexpected. In 2012 Ukraine decided to increase its annual defense spending 30 percent. The Ukrainian armed forces had long been in need of updating but since the early 1990s a shortage of cash delayed any attempt to get this process started. With the 2012 budget increase Ukraine planned to upgrade existing weapons and buy new warships and combat aircraft.
The new $2 billion budget was 1.1 percent of GDP. It had been .8 percent of GDP for the previous few years. The average for East European nations was then about 1.3 percent and many of the other East European nations long dominated by the Soviet Union were afraid that the Russians were seriously considering putting their empire back together. The other big problem was that Ukrainian military thinking and practices are still closely linked with the "Red Army" (the armed forces of the Russia). Nearly all Ukrainian military equipment and weapons were still Russian in 2014. Before, and after, 1991, a large portion of the Ukrainian export market was driven by factories that manufactured Russian designed weapons. Ironically, for the last 20 years these Ukrainian weapons industry have prospered, even though the Ukrainian military could not afford to buy most of these newly built weapons. But export customers could.
Unlike Russia, Ukraine doesn't have oil and gas exports to finance rebuilding of their armed forces. Ukraine spends barely enough to keep its force of 156,000 active duty troops going. Because it uses conscription it could quickly mobilize over half a million more troops, who are equipped with even more ancient and decrepit gear.
Ukraine split from the Soviet Union (and Russia) in 1991 when the Soviet Union dissolved. Many Soviet weapons plants were in Ukraine, as well as huge quantities of military equipment. That's because Ukraine was the forward staging area for Soviet forces that were to invade Western Europe, or defend against NATO. Ukraine inherited whatever was on its territory when the dissolution took place. Ukraine kept some of those weapons plants going by becoming the low-cost provider of new Russian designed weapons. By the late 1990s a lot of this stuff was being updated by Ukrainian engineers.
While friendly with the United States Ukraine has also cultivated good relations with China by quietly sending the Chinese examples of advanced Soviet weapons (including some that never went into mass production). Ukraine wanted to be on good terms with the U.S. and China because of the fear that Russia would try to make Ukraine, once more, part of Russia. This first happened in the 17th century and the Ukrainians never got used to it. Actually, Ukraine had been dismembered before that by Poles, Lithuanians, and Mongols. Thus Ukraine is enjoying its first period of real independence in over 500 years. They want to keep it that way but the Russians are threatening to end Ukrainian independence once more and all Ukraine has to defend itself with is a decrepit military equipped and led like Cold War era Soviets.