The Russian leader has decided that if Western countries don’t keep their commitments, neither should he.

The United States on Monday accused Russia of violating a Cold War arms treaty governing both powers’ use of intermediate range missiles. If true, it marks the latest in a series of Russian breaches of international norms since Vladimir Putin returned to the presidency in 2012.

Russia’s violation of the 1987 Intermediate Range Nuclear Forces Treaty, which prohibits both America and Russia from deploying ballistic and cruise missiles that are launched from the ground and have a range of between 500 and 5,000 kilometers, was first reported by The New York Times in January. An American government official confirmed the transgression this week, saying, “This is a very serious matter which we have attempted to address with Russia for some time now.”

While the official did not elaborate on how Russia had violated the treaty, Undersecretary of State for Arms Control and International Security Rose Gottemoeller said in May the country was developing a new ground-launched cruise missile.

The news comes at a time of renewed East-West tension as the United States accuse Russia of fueling a bloody separatist uprising in the east of its former satellite state Ukraine and Putin rallies against Western meddling in the affairs of sovereign states — especially those within what Russia considers to be its sphere of interest.

If true, the treaty violation underlines Russia’s increasing disregard of its international commitments. Most recently, it went back on a promise it made in the 1994 Budapest Memorandum to respect Ukraine’s borders and independence when it invaded the country in March and annexed the Crimea.

It wasn’t too long ago that Russia not only played by the rules but strongly advocated them.

In 2012, it joined the World Trade Organization after more than a decade of negotiations, subjecting its economy to international finance and trade laws.

A year earlier, Russia had criticized Arab and Western powers’ intervention in Libya’s civil war, arguing that their self-assumed “responsibility to protect” civilians from the brutality of dictator Muammar Gaddafi threatened to erode an international system that is based on the sovereignty of states.

It used the same argument against the possibility of military intervention in Syria where the regime of President Bashar Assad, a Russian ally, is estimated to have killed tens of thousands of civilians in an effort to put down a rebellion.

Yet to justify the Crimea’s annexation, self-determination — another Western moral code Russia claims to respect whenever it suits its interests — played a secondary role to its professed responsibility to protect ethnic Russians and Russian speakers in the Black Sea peninsula from a supposedly “fascist” regime in Kiev.

By appealing so overtly to ethnic nationalism, Putin not only perverted the very liberal interventionist doctrine his government vehemently criticized just three years earlier; he imperiled his Eurasian Economic Union with former Soviet republics Belarus and Kazakhstan which are interested in deepening trade relations with Russia, not in being drawn into a neo-imperialist scheme that could privilege their Russophone minorities over their own citizens.

Most Russians, however, are supportive of what they see as Putin standing up to an arrogant and hypocritical West. Polling from the Levada Center shows that 64 percent blame the West for the conflict in Ukraine while 61 percent dismiss the sanctions European countries and the United States have imposed on Russia since it began to support the uprising there.

Even as Russia’s $2 trillion economy is teetering on the brink of recession, partly as a result of the sanctions, and capital flight has accelerated to $75 billion this year, business leaders refuse to speak out — perhaps fearing that criticizing Putin could cause more harm to their companies than the sanctions themselves.

Rather, on Tuesday, there was a defiant reaction in Russia to an international arbitration court ruling that the country must pay $50 billion for expropriating the assets of oil company Yukos in 2004. When a popular radio show asked its listeners if Russia should withdraw from international courts altogether, 78 percent of respondents said “yes.”

The national mood helps explain Putin’s high approval ratings, despite what many observers in the West regard as his self-defeating policy, and stems from a sense of betrayal by the West.

While the Russians were apprehensive about military intervention in Libya, they acquiesced to a United Nations Security Council resolution that gave outside powers the right to use military force in order to protect civilians in the North African country. As the Russians see it, NATO and Arab allies seized on this mandate to engineer regime change in Tripoli. Bombings of government buildings and military assets enabled rebels to murder Gaddafi and bring down his regime.

Robert Gates, America’s defense secretary at the time, told The New York Times last year, “The Russians felt they had been played for suckers on Libya. They felt there had been a bait and switch. I said at the time we would pay hell ever getting them to cooperate in the future.”

Indeed, the Russians saw it “as part of a continuum of illegitimate and even imperialistic American interventions from Kosovo under President Bill Clinton to Iraq under President George W. Bush,” according to the same newspaper.

Alexei K. Pushkov, a professor of diplomacy and international relations at the Moscow Institute of International Relations, traced the list of Russian grievances back further in The National Interest in 2007, pointing out that NATO’s expansion following the end of the Cold War broke what the Russians had considered to be a promise from Western leaders not to threaten their security during such a precarious time for them. In 1999, the alliance also broke a treaty obligation to coordinate with Russia before it came to Kosovo’s defense and bombed Serbia, a Russian client state.

After he first came to power in 2000, Putin nevertheless backed the United States in the wake of the September 11, 2001 terrorist attacks, allowing American military bases to be opened in Central Asia to facilitate the war effort in Afghanistan. He also permitted overflights of Russian territory by American warplanes. For “an old cold warrior” like Gates, sending American military personnel to war through Russia was “never in my wildest imaginings,” he said last year.

In November 2001, Russia shut its listening post in Lourdes, Cuba. The following year, it did not make an issue when the United States unilaterally withdrew from the 1972 Antiballistic Missile Treaty with Russia. “What Putin was hoping for was a tacit agreement that, in turn, the United States would not encroach on those of Russia’s priorities that did not have a major importance to America,” Pushkov wrote.

Yet in late 2004, the Americans expressed support for the Orange Revolution in Ukraine that brought down the relatively pro-Russian president Viktor Yanukovich in favor of more pro-Western leaders. Yanukovich was forced to resign for a second time earlier this year when mass protests erupted against his decision to pull out of an association agreement with the European Union. What Russia describes as a “coup” set off the latest crisis in its relations with the West.

In 2006, in another affront to Russia, the United States announced plans to erect a missile shield in Central Europe with interceptors and control stations in the Czech Republic and Poland. While aimed at Iran, the Russians saw the system as undermining their nuclear deterrent. Plans to also establish radar posts in Azerbaijan, Georgia and Ukraine did little to placate their concerns, nor did NATO’s promise in 2008 that Georgia and Ukraine would “become members” of the alliance.

President Barack Obama clarified earlier this year that it would be “unrealistic” to expect either country to join NATO soon but Russia sees the West as nibbling away at its frontier nevertheless, supporting anti-Russian protest movements and gradually taking over the few allies and buffer states it has left.

Meanwhile, Western countries insist they have no designs on containing, let alone humiliating Russia. Yet that is what their policies accomplish. It is difficult for the average Russian, who is prone to believe in conspiracy theories and used to state authorities trying to deceive him, to believe this is all by accident.

Whatever Putin’s beliefs, he appears to have decided that if the West doesn’t keep its promises, he doesn’t have to either. And the majority of Russians will support him in that.