'Where do they stop?' U.S. veterans, officials explain why protecting Europe from Russia matters

RALEIGH, N.C. (WTVD) -- Adolf Hitler is long gone, and so is the Soviet Union, but nearly 80,000 American servicemen and women remain in Europe nearly 80 years after World War II.

This week, an additional 2,000 troops from Fort Bragg arrived in Poland and Germany as tensions simmer in a continent that, despite its centuries of bloodshed, hasn't experienced a major military conflict since 1945.

"There's no alliance in the history of this world that works as well as this alliance does," Sen. Thom Tillis, R-NC, said of the U.S.' commitment to NATO, the North Atlantic Treaty Organization. "It matters because the free world rests on a strong America, and a strong America rests on the strong relationships and alliances that we have built over the years NATO has been in existence."

The alliance now is dominated by a growing threat from Russia to invade Ukraine, a democratic nation-state of 44 million people that for years endured a harsh existence under the former Soviet Union.

"Hopefully this will de-escalate, and the Ukrainian people will be left alone, and we can avoid what would be a humanitarian crisis, a refugee crisis, and cause civilian casualties and military casualties," Tillis said.

The U.S. and Russia: From World War II to the Cold War to the War on Terror

Indeed, Russia and the U.S. needed each other to defeat the Nazis and the Axis Powers in World War II, but a common enemy could only go so far with these temporary friends. In 1949, the United States, the United Kingdom, France, and other Western European democracies formed NATO to double down on the alliance that had just defeated the fascist Nazi regime.

In Eastern Europe, however, the socialist influence of Josef Stalin and the Soviet Union created a competing bloc of oppressive authoritarian states that imposed strict restrictions on its citizens.

The United States and the Soviet Union would then engage in a cold war of fear, friction and attrition for the next 40 years. The conflict between the superpowers, moreover, would spill into Soviet proxies in the Middle East, Cuba and Vietnam, along with tensions over trade routes, commerce and natural resources.

Despite ample nuclear threats and staredowns, however, the Cold War ended without a shot fired in 1989, while the Soviet Union dissolved in 1991. Free from the grip of communism, several new and independent nation-states emerged from the Baltics to the Mediterranean that hoped to emulate Western-style democracies.

One of those nations was Ukraine.

"The American people need to understand that even though we're an ocean away, the safety and security of Europe is intrinsically linked with the safety and security of the United States," Tillis told ABC11. That's why it's important."

The American military presence in Europe, meanwhile, would remain and become a bridge for U.S. forces to more distant conflicts starting with the Gulf War and then the War on Terror.

Plus, after decades of the U.S. coming to the aid of Europe, NATO member states almost immediately joined coalition forces to fight alongside American troops in Iraq and Afghanistan.

Vladimir Putin and the Russian invasion of Crimea

Even with the U.S. embroiled in wars in the Middle East, the focus of NATO and U.S. Army Europe never fully moved away from Russia as its leader Vladimir Putin strengthened his hold on power and dominated his political opponents.

Putin, a child of the Cold War and former intelligence agent, called the collapse of the Soviet Union "the greatest geopolitical catastrophe." He twice won election as President in 2000 and 2004, and despite being barred from running for a third consecutive term, he maneuvered his way back into power as Prime Minister in 2008 and then again as president in 2012 - and hasn't left since.

According to U.S. officials, Putin has suppressed free speech while also cracking down on and even poisoning political opponents. He's also sought to maximize control of oil and gas supplies. In 2014, Russia invaded Crimea, a peninsula in Ukraine, marking the first territorial occupation since the Cold War.

Lt. Col. Marty Martinez (Ret.), a Fort Bragg veteran who spent three years in Europe, said NATO commanders immediately took notice.

"Some of the partners, some of the allies that are closer to the bear, are saying, 'Hey guys don't forget about us. We're over here and what are you going to do?'"

Martinez was a major when he deployed to Germany and was in charge of planning exercises between U.S. military personnel and NATO allies.

"What came from them is this real fear that if we do not do something, then they're going to be lost back into the fold of Russia. Where do they stop? They can roll in a matter of days to Estonia all the way down to Poland and then they're in Germany, literally."

The Russian threat: real or perceived?

The Department of Homeland Security warned law enforcement agencies on Jan. 23 that Russia would consider initiating a cyberattack on the U.S., including possible actions against critical infrastructure if it perceived the response to an invasion of Ukraine "threatened its long-term national security."

Even before the current tensions, however, U.S. intelligence officials concluded Russia meddled in the 2016 election, while their current nefarious activities threaten the disruption of more U.S. infrastructure and even health systems.

As for its potential pursuit of Ukraine, U.S. Defense Secretary Lloyd Austin and Chairman of the Joint Chiefs of Staff Mark Milley said that Russia now has amassed enough military forces to move on Ukraine, possibly even its largest cities.

"We don't believe that President Putin has made a final decision to use these forces against Ukraine. He clearly now has that capability, and there are multiple options available to him," Austin said. "Including the seizure of cities and significant territories" or "provocative political acts like the recognition of breakaway territories."

Russia has demanded guarantees that NATO never admits Ukraine and other ex-Soviet nations as members and that the alliance roll back troop deployments in other former Soviet bloc countries, a region Moscow still views as key to its own territorial integrity.

What happens next: Diplomacy or War?

Less than 24 hours after getting their orders from President Joe Biden, the first wave of U.S. troops deploying to Eastern Europe took off aboard C-17s from Pope Army Airfield at Fort Bragg on Thursday afternoon.

In all, 2,000 soldiers and paratroopers from XVIII Airborne Corps and the 82nd Airborne Div. deployed to Germany and Poland, among them Lt. Col. Jonathan Martinez - Marty Martinez's brother.

"You hope that nothing bad comes of this," Marty Martinez told ABC11. "It's a lot of saber-rattling, and they go away. But we don't know."

John Kirby, Pentagon Press Secretary, pointed to the force's versatility and readiness as the reason they were being ordered to lead the way on the mission to bolster NATO allies and deter Russian aggression as Russian President Vladimir Putin has refused to pull back troops from its border with Ukraine.

The Pentagon also has put about 8,500 U.S.-based troops on higher alert for possible deployment to Europe as additional reassurance to allies, and officials have indicated the possibility that additional units could be placed on higher alert soon.

Still, defense officials - and lawmakers - insist the soldiers are not there to fight a war. Diplomatic efforts are ongoing, according to senior members of the Biden administration.

"We've made clear that we're prepared to address our concerns, Ukrainian concerns and Russian concerns at the diplomatic table, but it cannot be done on the battlefield," U.S. Ambassador to the United Nations Linda Thomas-Greenfield said on ABC's "This Week". "We've seen the Russian playbook before."

ABC11's Andrea Blanford and The Associated Press contributed to this report.