(CNN) Call them provocations, aggressions or mere maneuvers, but the actions by Russia echo the bygone Cold War, ended a quarter century ago, analysts say.

Consider this year alone: Russian leader Vladimir Putin announces he's adding more nuclear missiles and is building a new generation of non-nuclear ones that could strike U.S. soil. Also, Russia's military intervenes in Syria, more than year after it annexed Crimea in Ukraine.

Then there's the Russian submarines triggering U.S. alarms as they near undersea cables, the Russian warship in waters off the U.S. East Coast, and this week's Russian reconnaissance planes in the Pacific flying too close to the USS Ronald Reagan -- whose namesake president is credited with ending the Cold War.

It's enough to raise a question as provocative as Russia's conduct itself: Are shades of a new Cold War emerging?

"In recent months, press reports and pundits alike have been all too eager to call the current conflict with Russia the 'Second Cold War,'" wrote American Foreign Policy Council research associate Dmytro Hryckowian.

"Indeed, as Russia threatens anew a nuclear buildup and NATO increases its forces in Eastern Europe, the situation seems to have regressed half a century," Hryckowian wrote in an August op-ed for U.S. News & World Report.

But the continuing tensions don't make for "a new Cold War" because the Kremlin today is more interested in territorial expansion and ultranationalist rhetoric than the Cold War dogma of communist revolution, Hryckowian said.

Still, the recent East-West faceoffs have been severe enough for one analysis to warn of "dangerous brinkmanship" in a report about 40 close military encounters between Russia and the West last year.

'The new Soviet Union'

CNN military analyst Lt. Gen. Mark Hertling said Putin is trying to build a "new Soviet Union," a Cold War reference to Russia, by intervening in nearby countries and countries farther away.

"I think what we're seeing right now is an attempt by Mr. Putin to go from the strategic defensive to the strategic offense, not only in Ukraine, not only in Syria, but other places like Moldova, threatening Poland, threatening the Baltic," Hertling said.

Photos: Tense moments between Obama and Putin Photos: Tense moments between Obama and Putin Barack Obama and Russian President Valdimir Putin toast during a luncheon hosted by United Nations Secretary-General Ban Ki-moon during the 70th annual U.N. General Assembly on September 28 in New York City. Hide Caption 1 of 7 Photos: Tense moments between Obama and Putin Obama and Putin shake hands while posing for a photo ahead of their meeting at U.N. headquarters on September 28 in New York. Hide Caption 2 of 7 Photos: Tense moments between Obama and Putin Putin speaks with Obama during the Asia-Pacific Economic Cooperation summit in Beijing, China on November 11, 2014. U.S.-Russia relations have descended to a new low since Russia annexed Crimea in March. Hide Caption 3 of 7 Photos: Tense moments between Obama and Putin Obama and Putin share a comical and awkward moment on a large split-screen during an international ceremony on the stretch code-named Sword Beach, in Ouistreham, France, to commemorate the Allied invasion of Normandy on June 6, 2014. Obama and Putin had an informal 15-minute chat during lunch at the ceremony that marked the 70th anniversary of the D-day landings. "It's a positive thing that they spoke, but more needs to be done," a senior U.S. official said at the time. Hide Caption 4 of 7 Photos: Tense moments between Obama and Putin Putin greets Obama at the G-20 summit on September 5, 2013 in St. Petersburg, Russia. The United States and Russia have been squaring off over the bloody civil war in Syria. Hide Caption 5 of 7 Photos: Tense moments between Obama and Putin Obama listens to Putin after their bilateral meeting in Los Cabos, Mexico on June 18, 2012 on the sidelines of the G-20 summit. The meeting was the first time Obama and Putin held face-to-face talks since Putin returned to the president's office earlier that year. Obama said he and Putin discussed the conflict in Syria and "agreed that we need to see a cessation of the violence, that a political process has to be created to prevent civil war." Hide Caption 6 of 7 Photos: Tense moments between Obama and Putin Obama, who had become U.S. President six months earlier, enjoys tea with then-Prime Minister Vladimir Putin and members of the American delegation at Putin's dacha on July 7, 2009 in Moscow. Hide Caption 7 of 7

"So, you're going to see continued emphasis by Mr. Putin to go places where Russia has not gone before to strengthen their empire and perhaps even bring back what many people are calling the new Soviet Union," Hertling said.

Earlier this month, U.S. Defense Secretary Ashton Carter declared Russia "a serious challenge" and said its "aggressions" are "a new reality for us."

"We will take all necessary steps to deter Russia's malign and destabilizing influence, coercion and aggression," Carter told the Association of the U.S. Army annual convention. "This is a new reality for us strategically, and it looks like it's here to stay."

Carter accused Russia of undermining the sovereignty of neighboring countries and destabilizing European security by annexing Crimea.

Back to a Cold War 'chess board'

In the Syrian civil war, the Russian military has stepped up its presence by land, air and sea, and Russian officials have contended their weaponry is targeting ISIS extremists and their infrastructure.

Photos: Sharing secrets: U.S. intelligence leaks Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – John Walker ran a father and son spy ring, passing classified material to the Soviet Union from 1967 to 1985. Walker was a Navy communication specialist with financial difficulties when he walked into the Soviet Embassy and sold a piece of cyphering equipment. Navy and Defense officials said that Walker enabled the Soviet Union to unscramble military communications and pinpoint the location of U.S. submarines at all times. As part of his plea deal, prosecutors promised leniency for Walker's son Michael Walker, a former Navy seaman. Click through the gallery to see other high-profile leak scandals the United States has seen over the years. Hide Caption 1 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Military analyst Daniel Ellsberg leaked the 7,000-page Pentagon Papers in 1971. The top-secret documents revealed that senior American leaders, including three presidents, knew the Vietnam War was an unwinnable, tragic quagmire. Further, they showed that the government had lied to Congress and the public about the progress of the war. Ellsberg surrendered to authorities and was charged as a spy. During his trial, the court learned that President Richard Nixon's administration had embarked on a campaign to discredit Ellsberg, illegally wiretapping him and breaking into his psychiatrist's office. All charges against him were dropped. Since then he has lived a relatively quiet life as a respected author and lecturer. Hide Caption 2 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Jonathan Pollard is a divisive figure in U.S.-Israeli relations. The former U.S. Navy intelligence analyst was caught spying for Israel in 1985 and was sentenced in 1987 to life imprisonment. Previously, the United States and Israel discussed his possible release as part of efforts to save fragile Middle East peace negotiations, according to sources familiar with the talks. On July 28, 2015, Pollard's lawyer announced that the convicted spy had been granted parole and would be released on November 21 -- exactly 30 years after his arrest. Hide Caption 3 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Wen Ho Lee was a scientist at the Los Alamos Laboratory in New Mexico who was charged with 59 counts of downloading classified information onto computer tapes and passing it to China. Lee eventually agreed to plead guilty to a count of mishandling classified information after prosecutors deemed their case to be too weak. He was released after nine months in solitary confinement. Lee later received a $1.6 million in separate settlements with the government and five news agencies after he sued them, accusing the government of leaking damaging information about him to the media. Hide Caption 4 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Members of the Bush administration were accused retaliating against Valerie Plame, pictured, by blowing her cover in 2003 as a U.S. intelligence operative, after her husband, former Ambassador Joe Wilson, wrote a series of New York Times op-eds questioning the basis of certain facts the administration used to make the argument to go to war in Iraq. Hide Caption 5 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – In 2007, Lewis "Scooter" Libby, Vice President Dick Cheney's former chief of staff, was convicted on charges related to the leak of the identity of CIA operative Valerie Plame. Libby was convicted of obstruction of justice and perjury in connection with the case. His 30-month sentence was commuted by President George W. Bush. Cheney told a special prosecutor in 2004 that he had no idea who leaked the information. Hide Caption 6 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Aldrich Ames, a 31-year CIA employee, pleaded guilty to espionage charges in 1994 and was sentenced to life in prison. Ames was a CIA case worker who specialized in Soviet intelligence services and had been passing classified information to the KGB since 1985. U.S. intelligence officials believe that information passed along by Ames led to the arrest and execution of Russian officials they had recruited to spy for them. Hide Caption 7 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Robert Hanssen pleaded guilty to espionage charges in 2001 in return for the government not seeking the death penalty. Hanssen began spying for the Soviet Union in 1979, three years after going to work for the FBI and prosecutors said he collected $1.4 million for the information he turned over to the Cold War enemy. In 1981, Hanssen's wife caught him with classified documents and convinced him to stop spying, but he started passing secrets to the Soviets again four years later. In 1991, he broke off relations with the KGB, but resumed his espionage career in 1999, this time with the Russian Intelligence Service. He was arrested after making a drop in a Virginia park in 2001. Hide Caption 8 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Army Pvt. Bradley Manning was convicted July 30 of stealing and disseminating 750,000 pages of classified documents and videos to WikiLeaks, and the counts against him included violations of the Espionage Act. He was found guilty of 20 of the 22 charges but acquitted of the most serious charge -- aiding the enemy. Manning was sentenced to 35 years in military prison in 2013. Hide Caption 9 of 10 Photos: Sharing secrets: U.S. intelligence leaks Sharing secrets: U.S. intelligence leaks – Former intelligence contractor Edward Snowden revealed himself as the leaker of details of U.S. government surveillance programs run by the U.S. National Security Agency to track cell phone calls and monitor the e-mail and Internet traffic of virtually all Americans. Snowden has been granted temporary asylum in Russia after initially fleeing to Hong Kong. He has been charged with three felony counts, including violations of the U.S. Espionage Act, over the leaks. Hide Caption 10 of 10

"The goal is terrorism. And we are not supporting anyone against their own people. We fight terrorists. As far as I understand, the coalition announced ISIL and other associated groups as the enemy. And the coalition does the same as Russia," Russian Foreign Minister Sergey Lavrov said.

But some analysts liken the Syria conflict to an emerging proxy war between Russia and the United States, just like in the old days of the Cold War.

"We're back to the geostrategic chess board, and this is Russia's move. They put a knight into the Middle East, so to speak. A chess piece. They pole-vaulted over Turkey, and now they've got their base established," said former NATO Supreme Allied Commander Wesley Clark.

U.S. officials have accused the Kremlin of using its military to support Syrian ally and President Bashar al-Assad and targeting anti-regime rebels.

Russian expansion

In one incident this month over Syria, the U.S. military diverted two F-16s that came within 20 miles of a Russian fighter aircraft.

The diversion is designed to prevent accidents and unintended conflict, said Maj. Gen. James "Spider" Marks, another CNN military analyst.

Photos: Russian warplane intercepts Photos: Russian warplane intercepts A Russian Tu-95 Bear bomber is escorted by a British Royal Air Force Typhoon fighter during an intercept in September 2014. Click through the gallery to see other intercepts in late 2014. Hide Caption 1 of 12 Photos: Russian warplane intercepts NATO Secretary General Jens Stoltenberg said in November that alliance fighters had intercepted Russian warplanes as they flew close to NATO countries more than 400 times in 2014, the kind of Russian air activity not seen since the Cold War. Hide Caption 2 of 12 Photos: Russian warplane intercepts An armed MiG-31 intercepted by Norwegian planes. The plane is nicknamed the Foxhound by NATO. Hide Caption 3 of 12 Photos: Russian warplane intercepts An armed Tu-22M supersonic bomber, nicknamed the Backfire by NATO, was photographed by Norwegian fighter jets. Hide Caption 4 of 12 Photos: Russian warplane intercepts A look at a Russian Tu-22M from below as taken by a Norwegian Royal Air Force fighter plane. Hide Caption 5 of 12 Photos: Russian warplane intercepts A Su-24 attack aircraft, nicknamed the Fencer by NATO, was photographed by a Norwegian warplane. Hide Caption 6 of 12 Photos: Russian warplane intercepts An armed MiG-31 Foxhound photographed from below by a Norwegian Royal Air Force interceptor. Hide Caption 7 of 12 Photos: Russian warplane intercepts A Russian Il-78 tanker refuels a Tu-95 Bear bomber in a photograph taken by a Norwegian warplane. Hide Caption 8 of 12 Photos: Russian warplane intercepts Two Russian Sukhoi Su-34 fighter bombers, nicknamed the Fullback by NATO, as photographed by Finnish Air Force F/A-18 Hornet fighters. Hide Caption 9 of 12 Photos: Russian warplane intercepts Finnish fighter jets photographed this Russian Tu-95 Bear bomber. Hide Caption 10 of 12 Photos: Russian warplane intercepts Two Tupolev Tu-22M aircraft intercepted by Finnish fighter planes. Hide Caption 11 of 12 Photos: Russian warplane intercepts A Russian Tupolev Tu-95 Bear bomber intercepted by Finnish fighter planes. Hide Caption 12 of 12

"What we don't want to do is pick a fight with Russia. We have never had a hot war with Russia or with the Soviet Union, and we don't want to do that," Marks said.

If anything, Cold War rhetoric thrives again.

"I would say even in Poland and Czech Republic and talking to people from those countries, they are concerned about the expansion of Russia," U.S. Rep. Peter King, a member of the House intelligence and Homeland Security committees told CNN recently. "We have to make it clear that, just as it was during the Cold War, that if we have to, the U.S. and the Western alliance will come together to stop Soviet aggression."