Russia’s war in Ukraine hit the six-month milestone Wednesday after Moscow launched a brutal ground invasion on Feb. 24, 2022. 

Europe has not seen a war this brutal or hard fought since World War II as fighting continues in the trenches and the sky while deadly shelling continues to pummel Ukraine's 1,500-mile long frontline.

NATO chief Jens Stotlenberg on Tuesday referred to the fighting as a "grinding war of attrition" that will come down to a "battle of wills and a battle of logistics."

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Western allies, NATO and Kyiv have championed Ukraine’s ability to hold off Russian forces as a major success, and Ukrainian defense officials have said they plan to turn the tide on Russia with a major counter-offensive.

Both sides remain largely stalled with the U.K. defense ministry assessing Wednesday that Russia has made "minimal progress" as major battlefronts remain highly contested from Ukraine’s north in Kharkiv to its southern port city of Mykolaiv.

However, despite Ukrainian claims that it has a counter-offensive plan, Russia expert and former intelligence officer for the Defense Intelligence Agency (DIA), Rebekah Koffler, told Fox News that Russian President Vladimir Putin will also be using this moment to strategize. 

"With the Russia-Ukraine stalemate in the actual theater of combat operations, the battlefield has expanded into the rear, behind the enemy lines," she said. "Putin needs to rethink strategy now. It takes time to plan something dramatic and meaningful from the military standpoint, that would change the balance of forces and the dynamics on the battlefield."

Ukrainian President Volodymyr Zelenksyy warned that Russia could be planning "something particularly nasty" and "particularly cruel" for Ukraine’s Independence Day Wednesday. 

Ukraine has yet to see anything out of the ordinary in the way of kinetic military action.

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Koffler warned that given recent events involving the assassination of the daughter of top Putin ally Alexander Dugin and recent attacks in Crimea, Russia will not sit idle. 

"Putin will almost certainly escalate [the war] and is likely looking for the best opportune moment," Koffler explained. Additionally, she believes Putin could be "planning to do something big," like a crippling cyber-attack. 

"Russia is big on symbolism and this is why it launches attacks or non-kinetic strikes on national holidays that are meaningful for the adversary," she continued. "To shake the adversary psychologically and make maximum impact."

Putin, who has refused to refer to his war as an invasion and instead has dubbed it a "special military operation," has claimed that Russia has yet to throw its full might at Ukraine. 

Western defense officials in July countered this and a senior U.S. defense official told Fox News that Russia is using 85% its fighting force.

However, concerns remain high that Russia could turn to nuclear weapons – a threat Koffler warned could become increasingly likely as the war once again shifts with renewed focus on Crimea. 

Though Ukraine is still working to repel Russian forces from territory it has captured since its February, Kyiv has already made a point to say it will not cease its counter-offensive until it restores all of its sovereignty – including in Crimea. 

Russia annexed the southern peninsula in 2014, though the international community and Ukraine view this annexation as illegitimate.

As the focus shifts to Crimea, Koffler warned this could escalate the war even further.

"Ukraine is highly unlikely to take back Crimea without significant support from NATO," she said, noting that direct NATO’s involvement in Crimea could "escalate the conflict into the nuclear realm."

The U.S. and NATO have stood firm on their refusal to put boots on the ground in Ukraine. But Russia has already claimed that the significant arms support Ukraine has received amounts to "direct" involvement in the war.

"Russia considers Crimea as Russian territory now," Koffler said. "It would give Putin the pretext to expand the conflict dramatically, into the next level on the escalation ladder."