The Ukrainian Army can look powerful or weak in eastern Ukraine, depending on the battle.
Its performance has included a significant success in retaking the Donetsk international airport from insurgents on May 26 but beyond that has been characterized by a mixed record at best and some notable setbacks at worst.
The mixed record was on display this week as outnumbered border guards in Luhansk on June 2 called in help from the Ukrainian special forces and air force to repulse three waves of attacks by insurgents in a battle that Kyiv said killed five rebels and left and four government soldiers critically injured.
Yet on June 4, Kyiv abandoned the outpost as Ukraine's Border Guards Service said the soldiers had been evacuated to unspecified "safe locations." Pro-Russian insurgents took over the base, seizing large quantities of munitions. They also seized a National Guard post in Luhansk in overnight fighting after forces there ran out of ammunition.
Two of the worst setbacks for the Ukrainian Army have occurred in skirmishes over insurgent checkpoints around the city of Slovyansk.
On May 29, rebels shot down a military helicopter deploying troops in a firefight near Slovyansk, killing 14 soldiers including a general. On May 2, insurgents shot down two reconnaissance helicopters near Slovyansk, killing two crew members.
Vladimir Grek, a military analyst and president of the Association of Ukrainian Defense Technologies in Kyiv, says the mixed performance reflects the uneven nature of the Ukrainian military itself. Elite units are well equipped but regular units have outdated equipment that makes them vulnerable to losses, he says.
In both [the Slovyansk and Donetsk operations] Mi-24 military helicopters were used," Grek notes. "But in the [Donetsk] case, they used modernized military helicopters that have missile-defense systems installed that send a false signal to a missile's target-seeking warhead and cause it to fly away from the helicopter."
A Ukrainian Mi-24 gunship fires its cannons at rebels at the main terminal building of Donetsk airport on May 26.
Grek says the missile-defense system that prevented any helicopters from being shot down in the Donetsk operation was designed and built by Ukraine's own defense industry. But lack of funding for modernizing the military means only some helicopters have the system, while most do not.
The lack of military funding has been chronic ever since Ukraine's independence in 1991 and now clearly handicaps the Ukrainian Army as it fights in eastern Ukraine.
Serhiy Zhurets, director of the Center for Army, Conversion, and Disarmament Studies research center in Kyiv, says "practically 100 percent of the weapons and equipment used in the Ukrainian armed forces were made in the late 1980s."
He estimates that in recent years the Ukrainian parliament has funded the military at 10 percent of what it needs to modernize. The Ukrainian military has said it needs 131 billion hryvnyas ($11.3 billion) to replace old weapons and machinery. But in 2013 the parliament allocated just 15.6 billion hryvnyas ($1.3 billion) for defense.
By contrast, Poland's defense budget is about $10 billion, Russia's is some $70 billion, and the United States' is around $640 billion.
NATO Secretary-General Anders Fogh Rasmussen announced on June 3 that the alliance will help Ukraine's military with a "comprehensive package of long-term measures to make Ukraine's reforms more effective and its armed forces stronger." He did not provide details other than that the package will be finalized in the coming weeks.
But poor equipment is not the only thing hampering the Ukrainian Army's performance.
Another is lack of combat experience. Ukrainian units have had some war-zone experience in recent years through international peacekeeping operations in Afghanistan, Iraq, and the Balkans. But Grek says that many soldiers once involved in those operations have long since left military service.
Yet another problem is the military's inability to use its overwhelming armor and air advantage against separatists who shelter in towns and cities.
Kyiv has gone slowly during the two months the separatists have waged their insurgency in order to avoid civilian casualties that could enflame public opinion against the government.
Now, the Ukrainian troops must play catch-up against a determined foe that has grown from a motley band of guerrillas into a force capable of launching major military assaults.
The June 2 attack on the border command center in Luhansk was a measure not just of how well armed the insurgents are but also of their strategic determination to keep their supply lines from Russia open for a protracted struggle.
Some observers say that what the Ukrainian Army needs most now is to begin racking up enough victories to finally get the momentum going in Kyiv's favor.
"If Kyiv can look as if it is beginning to turn the tide, first of all, that is going to make Kyiv's own forces feel better about themselves, which is an intangible but very real factor in warfare. And secondly, it may well begin to rattle the nerves of the militias of the east," says Mark Galeotti, a professor at New York University who specializes in post-Soviet security issues.
He adds, however, that the ultimate success of the Ukrainian Army against the insurgents depends on Russia. So far, Moscow has officially ignored the appeals of rebels in the Luhansk and Donetsk regions for help but also has done nothing to stop the flow of arms and irregular volunteers across its border.