Russian President Vladimir Putin is celebrating Victory Day in Simferopol today, admiring the Crimean peninsula that he so winningly stole from Ukraine this spring. Not too far away, in the city of Mariupol, Ukrainian police began the holiday with a deadly gun battle with separatists. Over 100 people have died in Ukraine since May 2, and despite reports that Ukraine's "anti-terrorist operation" was successfully driving out separatists in the east, it does not look like the fighting will stop anytime soon. Victory Day celebrations in Ukraine must carry an ironic tone today, as the conflict has revealed the extent to which its armed forces were systemically mismanaged since the country declared independence from the Soviet Union in 1991, leaving Ukraine almost entirely helpless to stave off the Russian invasion. Here are a few reasons why:

Ukraine inherited the Soviet military machine when it gained independence.

At the time, that meant Ukraine had the second-largest standing army in Europe, with some 750,000 troops. But the new government couldn’t afford to keep up such a large force, and began rapidly cutting costs. Since then, the Ukrainian Defense Ministry has been “consistently downsizing to a force of about 120,000, which they thought made sense,” said Steven Pifer, former U.S. ambassador to Ukraine (1998-2000). When Russia invaded Crimea, Ukraine was still in the process of downsizing, and had plans to further decrease its forces to 100,000 by 2017.

Soviet-era infrastructure remains the backbone of Ukraine’s army, which means that most military bases are located in the western part of the country, where they could fend off a NATO attack. (This map shows the relative dispersion of Ukrainian and Russian forces.) “The Ukrainian military inherited what was the Soviet military infrastructure for the Transcarpathian front. It was there to support a Soviet push across NATO’s southern flank,” said Jacob Kipp, a Eurasian Security expert at the Jamestown Foundation. After independence, there were no substantial efforts to build up the army’s defense capability in the east because, said Kipp, “Given the nature of Ukrainian politics, it was very difficult to say, ‘Okay we’re going to prepare ourselves to face a threat from Russia. There was no way you could talk about reorganizing the military to be ‘facing the Russians.’”

Soviet weapons stockpiles remain in Ukraine, where they are secured by Ukrainian armed forces. Slovyansk, where some of the deadliest clashes of the crisis have occurred, is also the location of a stockpile of some five million Soviet-era small arms, according to the British Royal United Services Institute. “The multiple seizures of government buildings in eastern Ukraine, not just in Slavyansk but also in Konstantinovka in Donetsk Oblast are aimed to make it impossible for Ukrainian forces to fully control the territory and, in effect, to cut it off from its strategic stockpile of light arms,” researchers at the institute found.