Two years after its unprovoked invasion of Ukraine, Russia has gained the upper hand, according to a new paper published by the Association of the U.S. Army.

“Considering the balance in relation to each state’s ends, Russia is currently winning the war,” Lt. Col. Amos Fox writes. “Russia controls significant portions of Ukrainian territory, and they are not likely to be evicted from that territory by any other means than brutal land warfare, which Ukraine cannot currently afford.”

In “The Russo-Ukrainian War: A Strategic Assessment Two Years into the Conflict,” Fox, a doctoral candidate at the University of Reading and a freelance writer and conflict scholar writing for AUSA, delves into the nuances behind the war.

Land wars, like the Russo-Ukrainian war, require a strategy that is “properly aligned” with a fight for control over territory, Fox writes.

“Russia’s strategy of exhaustion … appears to be working,” he writes. “A strategy built on the centrality of precision strike but lacking sufficient land forces to exploit the success of precision strike … will not win a war for territory—especially against an industrialized army built to fight and win wars of attrition.”

Though precision strike capabilities provided by the U.S. and its partners helped initially, Russia’s manpower is now overpowering Ukraine, Fox writes.

“Precision might provide a tactical victory at a single point on the battlefield, but those victories of a finite point are not likely to deliver strategic victory,” he writes. “Ultimately, Russia’s operations in Ukraine show that mass, especially in wars of territorial annexation, are how a state truly consolidates its gains and hedges those military victories against counterattacks.”

Russia and Ukraine likely will be locked in a stalemate until one of their armies is able to “outright defeat the other,” according to Fox.

“Kyiv’s ends exceed the limits of its means,” he writes. “If it is correct that Russian strategy is primarily concerned with retaining its territorial acquisitions … and that Ukrainian land forces do not have the numbers to… [attack, defeat and defend against Russian military forces], ... then the precision strike, drones and targeting information might be the window dressing for a futile strategic position.”

Until then, this “war of attrition” will continue to grind on, Fox writes.

“Ukraine’s inability to generate the size of force, coupled with the destructive warfighting capabilities needed to destroy Russia’s army in Ukraine and to occupy and hold the liberated territory, means that this war of attrition will likely grind on until either Ukraine can generate the force needed to evict Putin’s army from Ukraine, Ukraine becomes strategically exhausted and has to quit the conflict, or both parties decide to end the conflict,” he writes.

Read the paper here.