An entire generation of U.S. military forces have cut their teeth in the battlefields of Afghanistan and Iraq, but with Russia posing a new threat in Europe, they are having to relearn some old tricks.
U.S., North Atlantic Treaty Organization (NATO) and European forces recently completed Saber Guardian 2017, a 10-day long exercise in Hungary, Romania and Bulgaria - three countries on the front line with Russia.
More than 25,000 troops from more than 20 countries participated in the operation, making it the largest of all Black Sea region exercises.
"Saber Guardian has been a terrific opportunity for the alliance to improve its capability," said Army Lt. Gen. Ben Hodges, commander of U.S. Army Europe, while speaking in Bulgaria in late July.
U.S. troops worked with their European counterparts throughout the most dangerous parts of the Middle East, but now they are revisiting a battlefield many of them are completely unfamiliar with.
Aside from the obvious differences in terrain, the troops are having to learn a completely different set of tactics.
Working out of secure forward operating bases doesn't work on the European front, where Russia's modern artillery could make quick work of even the most fortified outpost.
Air superiority is also not guaranteed, as the Russians have highly capable air defense systems and attack aircraft, including drones.
But a new battlefield has not deterred U.S. forces from adapting to the new surroundings, and committing to the defense of both NATO and Europe as a whole.
"When the United States is serious about something, we put money on it and we put people on it," said Hodges. "And usually those people are young men and women of our armed forces."
Additional forces and joint exercises in Europe may help, but the U.S. and its partners are vastly outnumbered on the eastern European border.
A 2016 study by the RAND Corporation found that Russian forces could easily overrun NATO in the Baltics - Lithuania, Estonia and Latvia.
Experts gamed out the scenario and found that the Estonian capital of Tallin or the Lithuanian capital of Riga could be taken by the Russians in no more than 60 hours.
"Such a rapid defeat would leave NATO with a limited number of options, all bad," said the report, which recommended bolstering the exposed flank with seven brigades, the equivalent of 31,500 troops.
RAND admitted that even that amount would not be wholly sufficient to maintain a "sustained defense," but it would help change Moscow's point of view.
Russia not only has the manpower advantage, it is also currently engaged in a major military modernization program.
Russian forces also reportedly plan to conduct their own summer exercise near Eastern Europe later this summer. More than 100,000 troops are expected to participate, four times as many as Saber Guardian.
The situation may sound ominous, but Saber Guardian appears to have had a positive effect on wary European allies.
"We gained a kind of confidence that we're not alone here on the eastern flank of NATO," Brig. Gen. Theo Tader of the Romanian Air Force told the New York Times on Monday.
A May report by the Carnegie Endowment for International Peace additionally claimed that Russia is hardly invincible, nor has its military modernization program finished.
It would appear the U.S., NATO and Europe have some time to catch up, at least for the time being.