kraine faces a closing window of opportunity to avoid a "forever war" with Russia, an American special forces veteran now training Kyiv's troops has told Newsweek as Ukrainian soldiers press the ongoing counteroffensive in the south and east of the country.

Erik Kramer, the director and co-founder of the Kyiv-based Ukraine Defense Support Group (UDSG), said in an interview from Kyiv that Moscow's forces are well entrenched in the 20 percent of Ukrainian territory they still occupy, and that ejecting them will be a long and costly project for Ukraine's troops.

"It's going to be one of those forever wars," Kramer—who served the U.S. military for 26 years in locations including Afghanistan, Bosnia, Congo, Iraq, and Kosovo—said.

"The Russians have had months, if not years, to develop defense in depth. And the same things that were working against the Russian army—whether it's logistic lines, or logistic hubs, or these directed fires from the Ukrainians—also work against the Ukrainians when they're on the offense."

SUBSCRIBE NOW FROM JUST $1 >
"I do think there will be some success. But again, I think the lines will stabilize and you're going to have this low-boil forever war with lines just like they were close to 2014," Kramer added, referring to the frozen conflict that settled over the eastern Donbas region following Moscow's 2014 invasion of the Crimean peninsula.

"You always have to look at logistics and political will," the veteran added. "You can already see that the amount of stuff the West has given to Ukraine is depleting the West's ability to maintain a ready posture. I see it getting worse as the year goes on. I think less and less will be coming in."

At the July 11-12 NATO summit, Czech President Petr Pavel said Kyiv's "window of opportunity" to liberate land may close by the end of 2023, as worse weather and political conditions combine to increase pressure for negotiations with Moscow."I agree with the statement that it's this year or never," Kramer said.