One year ago today Russian tanks rolled into Ukraine, Europe entered into a security crisis not seen since World War II and Black Sea blockades created global shock waves that prompted worldwide food shortages.

Russian President Vladimir Putin allegedly believed his "special military operation" would take just days for his troops to storm across Ukraine and overthrow the capital of Kyiv – a belief that was shared by top U.S. officials. 

But instead, the world watched as the real time David vs. Goliath story unfolded and Ukrainian troops held strong against one of the largest, most sophisticated militaries in the world – stopping Putin in his tracks.

Basic logistical failures like fuel shortages stalled Russian efforts within the first week of the invasion, showing a level of unpreparedness in Moscow’s ranks that flabbergasted Western defense officials.

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But Russia’s inability to quickly take Ukraine has led to what many believe will be a prolonged war of attrition, with casualties already mounting to rates not seen in a Western conflict in some 80 years and concerns growing over how long Kyiv can hold out. 

"We are fighting a smart war," Yuriy Sak, top adviser to Ukraine’s defense minister, told Fox News Digital. "We are not prepared to use the tactics employed by the enemy, which is to use people as expendable resources – throwing them into this meat grinder, this slaughterhouse."

Experts are divided on how or when the war will end, but they agree many more casualties are expected. 

"The way that the Russian military fights is very different from the way that U.S. military and now Ukrainians being trained by the U.S. miliary [fight]," former Defense Intelligence Agency intel officer for Russian Doctrine & Strategy, Rebekah Koffler, said. "The Russians don't really care for loss of life."

Koffler pointed to Putin’s September mobilization order to add 300,000 Russian soldiers to his ranks, along with rumblings last month that suggested he may look to add another 500,000 conscripts. 

Moscow in January also detailed plans to expand its military to 1.5 million personnel by 2026, up from 1 million. 

Russia’s military expansion plans have been fueled by the West’s continuous pledges to back Ukraine for as long as it takes through arms support and humanitarian aid. 

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The Pentagon has long claimed that Russian arms supplies are dwindling and brutal fighting in eastern Ukraine has prompted Russia to throw what it can in droves at the front lines – bodies. 

"It is a relentless attrition of manpower," Koffler said. "And he's clearly preparing for a very, very protracted battle.

"He's just going to throw more young Russian men into the meat grinder," she added explaining that Moscow plans to exhaust Ukrainian forces through the sheer number of men it can add to its ranks. 

"Quantity does not necessarily mean a real battlefield advantage," Sak said, pointing to Russia’s months-long attempts to take Bakhmut. "It just means we need more ammunition to destroy them."

Defense officials and Ukrainian soldiers on the front lines have reported that the constant supply of Russian troops funneled into Ukraine are inadequately supplied, lack sufficient training and are being killed at increasing rates.

In mid-February a BBC Russia investigation found that in the confirmed deaths of over 1,000 conscripted men mobilized after Putin’s September order, 40% of them were killed after the 2023 New Year – signaling a spike in frontline deaths.

Kyiv has estimated that Russian forces have lost up to 1,000 men a day in the Bakhmut sector alone.

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The last official estimate on the number of deaths reported by the Biden administration came in November when Joint Chiefs Chairman General Mark Milley told reporters that 100,000 soldiers on each side of the lines were believed to have been killed. Russian deaths are now believed to be closer to 150,000 while Ukraine’s losses remain more ambiguous. 

"Their morale is down. It's exposed their bad logistics and bad tactics. The Russians are throwing a lot of cannon fodder. They're just grabbing guys from prisons, and showing absolutely no respect for the law in war – where you are supposed to distinguish between civilians and legitimate military targets," former CIA Moscow station chief Dan Hoffman told Fox News Digital in reference to Russia’s penal recruits for its Wagner mercenary group. 

NATO and Ukrainian defense officials have been sounding the alarm for months that Russia is planning a major offensive in an attempt to turn the tide in Ukraine. Moscow saw significant setbacks in the final months last year when Ukraine retook Kharkiv in September, damaged the Crimean bridge in October, and pushed Russian forces across the Dnieper River in November, securing the city of Kherson. 

It is now believed that Russia's offensive charge will come in waves closer to the spring time when the weather lets up and will likely not be one united push.

But Ukrainian Defense Minister Oleksii Reznikov told NATO partners just last week that despite the significant amount of arms and equipment that allies have recently pledged to Kyiv, it will take a couple of months for Ukraine to prepare an adequate counteroffensive. 

"It's a war in which tactics and equipment and the smart use of modern technologies are a decisive factor, not the sheer number of armed forces," Sak explained, pointing to how the battlefield dynamic in Ukraine shifted once Kyiv had received High Mobility Artillery Rocket Systems (HIMARS) last summer.

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"That was a turning point," he said. "We were able to reach the enemy – ammunition depots and command centers – deeper inside their territory.

"It's always important to try to be one step ahead of the enemy, not one step behind," Sak added.

Hoffman argued the West’s hesitancy and repeated decision reversals to send adequate aid to Ukraine is what has prolonged this war to begin with.

"We delayed. First, we said no on air defense then we gave it to them. Then we said no on tanks now we're giving it to them – it’s a year into the war," he said. "What is our strategy here?"

"Could Ukraine win? Yeah, they could win. They should win," Hoffman added. "If we gave them what they need to do it."

Hoffman's comments were near synonymous among defense experts following the announcement by Secretary of State Antony Blinken over the weekend that the U.S. is now concerned that China is considering giving Moscow lethal aid. 

"They're being too cautious," chief political scientist with the Atlantic Council Matthew Kroenig said. "[It] makes it more likely that this war goes on longer – makes it more likely to give time for things like China to intervene and help Russia."

Koffler took a bleaker view on the war’s future and argued providing arms will not be enough to end the war. 

"I think it's going to end with a settlement," she said. "It's unwinnable because of how the victory is defined right now."

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Koffler said Ukraine will only claim victory once it has repelled Russian forces from all of its borders, including Crimea, which Russia has illegally occupied since 2014. 

"Putin is just never going to let that happen," she added pointing to the Kremlin’s threat to escalate the war through the use of nuclear weapons. "For the Russians, their definition of victory is very different. Their definition of victory is really protracted war – denying victory to us."

Koffler argued that Putin’s true aim is in blocking Ukraine from being accepted into NATO, and so long as the nation is embroiled in a war it will not be eligible to join the military alliance.

The Russia expert warned that the war will continue until "the three parties come to the realization that they've killed enough people," she said in reference to Ukraine, Russia and the United States. 

"Until they realize it's time to wrap it up, it’s not going to happen," Koffler said, adding that she believes the war could continue for another two to five years. 

Kyiv has said it intends to conclude the war by the end of 2023, though this end date is appearing increasingly unlikely after the U.S. and NATO, along with Putin this week, vowed to continue the war effort. 

"We all should step up our efforts and shift into high gear so that we don’t allow this war to become a protracted war – it's not in the interest of anyone," Sak argued. "It's not just about Ukraine. It's about the stability of Europe and the world."

The Ukrainian defense adviser said that ultimately Ukraine will keep doing what it must in the continued face of Russian aggression – fight.

"Victory for us will mean not just throwing the enemy out and restoring our territorial sovereignty over all internationally recognized territories," Sak said. "Victory will also mean establishing a Ukraine which will make such aggression impossible in the future."