(SeaPRwire) –   This is the third installment of a series analyzing the challenges facing the NATO alliance.

LVIV, Ukraine — Four years after Russia launched its invasion of Ukraine, officials throughout NATO’s eastern flank are increasingly of the view that the alliance’s future is already being reshaped on Ukraine’s battlefields.

Spanning areas from drone combat and cyber defense to civilian preparedness and large-scale military mobilization, Eastern European officials note Ukraine has developed into one of the world’s most combat-proven armed forces, pushing NATO to reconsider how future conflicts will be waged.

This week, NATO Secretary General Mark Rutte confirmed that Ukrainian President Volodymyr Zelenskyy has been invited to attend the alliance’s yearly summit in Ankara this July, highlighting how integral Ukraine has become to NATO’s future even though it is not a member of the bloc.

“In my view, the Ukrainian military is the top-ranked army in Europe right now,” Lviv Mayor Andriy Sadovyi told Digital in an interview conducted in the western Ukrainian city.

“I believe NATO has a need for the Ukrainian military,” he went on to say.

Discussions over NATO’s future grew more heated this week as the alliance’s foreign ministers convened in Sweden ahead of the key July NATO summit, with Secretary of State Marco Rubio describing the upcoming gathering as “one of the most significant leaders’ summits in NATO’s history.”

Rubio issued a warning to NATO allies this week that the alliance does not have enough ammunition manufacturing capacity to meet future conflict needs, a concern shared by retired Lieutenant General Richard Newton, who noted the Pentagon is examining Ukraine’s fast-paced wartime industrial adjustments.

“Many countries are drawing lessons from Ukraine’s overhaul of its defense industrial base, both when it comes to quality and the massive rise in the volume of weapons reaching frontline positions,” Newton stated, adding, “The Pentagon is observing these developments and working to push for changes to our own industrial base, so that we can drastically enhance and much more quickly deliver capabilities to our deployed forces, not over a timeframe of years, but in months, or potentially even weeks.”

Rubio also mentioned President Donald Trump’s announcement that the U.S. will keep its troop deployments in Poland, following concerns raised earlier this week that troop levels on NATO’s eastern flank might be cut.

Speaking ahead of the NATO gathering, Polish Foreign Minister Radosław Sikorski expressed approval of Trump’s announcement. “I would like to thank President Trump for his announcement that U.S. troop presence in Poland will be kept at roughly the same levels as before,” Sikorski stated.

“I believe this will make Putin very uneasy.”

Some observers point out that the discussions surrounding NATO’s future carry a strong sense of irony for Moscow.

One of Russian President Vladimir Putin’s core complaints prior to the invasion was NATO’s eastward expansion and Ukraine’s increasing aspirations to align more closely with the alliance. Moscow repeatedly demanded that NATO scale back its military presence to 1997 levels and rejected any prospect of future Ukrainian membership.

On the contrary, the invasion sped up NATO’s expansion.

Finland officially became a NATO member in 2023, bringing an end to decades of military neutrality, while Sweden joined the alliance in 2024, after Russia’s invasion drastically altered security assessments across northern Europe. Finland’s accession alone added over 800 miles of direct shared border between NATO and Russia.

Now, officials in Poland and Ukraine say the war is not just growing NATO’s geographic reach, but also fundamentally changing the alliance from within.

“For decades, NATO primarily concentrated on expeditionary conflicts and counterterrorism efforts,” Polish Deputy Defense Minister Paweł Zalewski said in an interview in Warsaw. “Contemporary warfare relies heavily on drones.”

“No military on Earth is better than Ukraine’s” when it comes to grasping the realities of present-day battlefields, he added.

Retired General Philip Breedlove, who previously held the post of NATO Supreme Allied Commander Europe, said the war has completely changed how armed forces across the globe understand modern combat.

“The war in Ukraine has altered far more than just NATO’s grasp of modern warfare — it has shifted the entire world’s understanding,” Breedlove told Digital.

Breedlove went on to say that Ukraine’s military has developed into “one of Europe’s most capable and powerful” forces after years of combat against Russia, even though it gave up its Soviet-era nuclear stockpile under the 1994 Budapest Memorandum.

“Today, most people recognize that Ukraine is not just fighting, but also recapturing territory from one of the world’s most powerful military forces,” he stated.

This transformation is evident across all of Ukraine.

Prior to Russia’s invasion, Ukraine had one of the largest IT sectors in Eastern Europe. Sadovyi noted that the war pushed much of that technological ecosystem to shift its focus to defense manufacturing.

“Before the invasion, we had a massive IT cluster in Kyiv with 40,000 employees,” the Lviv mayor said. “Over the course of the war, we have redeveloped that IT cluster into a defense cluster.”

Ukraine now runs a fast-growing wartime innovation ecosystem centered on drones, anti-drone technologies, battlefield communications systems and decentralized weapons manufacturing. NATO officials and European armed forces are increasingly examining these lessons closely.

Breedlove notes that the conflict has laid bare the limitations of conventional air power and sped up the adoption of drone warfare.

“It is important to keep in mind that the war in Ukraine is essentially being waged without the support of modern air combat capabilities, due to the Russian Air Force’s shortcomings,” he said.

“That is the reason drone warfare has expanded so rapidly, as neither side has been able to deploy genuine modern air power capabilities.”

These shifts are also redefining NATO’s strategic approach.

Polish defense official Zalewski told Digital that the Pentagon is currently pushing what Polish officials refer to as “NATO 3.0”, a framework under which Europe takes on more responsibility for conventional defense, as the United States redirects more of its focus to China and the Indo-Pacific region.

“The core premise of this concept is that Europe would be responsible for its own conventional defense,” he stated.

This shift is taking place as Poland drastically ramps up its military spending and establishes itself as one of NATO’s top military powers on the alliance’s eastern flank. Warsaw allocated almost 5% of its GDP to defense this year, the highest share among all NATO members.

Polish officials contend that the war has proven Eastern Europe was correct to take the Russian threat seriously, long before many Western European nations did the same.

“The eastern flank is far more powerful than it was just five years ago,” Polish Deputy Foreign Minister Marcin Bosacki told Digital during reporting conducted in Warsaw.

“We were correct in our assessment of the nature of Putin’s regime and Russia’s aggressive strategy.”

Ukraine is not currently a member of NATO, and the alliance has declined to give Kyiv a clear timeline for joining during the war, over fears that doing so could spark a direct conflict between NATO and Russia.

But across Eastern Europe, officials are increasingly making the case that the alliance’s future may hinge on Ukraine, irrespective of its formal membership status.