Russia has thrown down a gauntlet that is not limited to Crimea or even Ukraine.
Mr. Putin aspires to restore Russia's global power and influence and to bring the now-independent states that were once part of the Soviet Union back into Moscow's orbit. While he has no apparent desire to recreate the Soviet Union (which would include responsibility for a number of economic basket cases), he is determined to create a Russian sphere of influence—political, economic and security—and dominance. There is no grand plan or strategy to do this, just opportunistic and ruthless aspiration. And patience.
Mr. Putin, who began his third, nonconsecutive presidential term in 2012, is playing a long game. He can afford to: Under the Russian Constitution, he could legally remain president until 2024. After the internal chaos of the 1990s, he has ruthlessly restored "order" to Russia, oblivious to protests at home and abroad over his repression of nascent Russian democracy and political freedoms.
In recent years, he has turned his authoritarian eyes on the "near-abroad." In 2008, the West did little as he invaded Georgia, and Russian troops still occupy the Abkhazia and South Ossetia regions. He has forced Armenia to break off its agreements with the European Union, and Moldova is under similar pressure.
Last November, through economic leverage and political muscle, he forced then-President Viktor Yanukovych to abort a Ukrainian agreement with the EU that would have drawn it toward the West. When Mr. Yanukovych, his minion, was ousted as a result, Mr. Putin seized Crimea and is now making ominous claims and military movements regarding all of eastern Ukraine.
Ukraine is central to Mr. Putin's vision of a pro-Russian bloc, partly because of its size and importantly because of Kiev's role as the birthplace of the Russian Empire more than a thousand years ago. He will not be satisfied or rest until a pro-Russian government is restored in Kiev.
He also has a dramatically different worldview than the leaders of Europe and the U.S. He does not share Western leaders' reverence for international law, the sanctity of borders, which Westerners' believe should only be changed through negotiation, due process and rule of law. He has no concern for human and political rights. Above all, Mr. Putin clings to a zero-sum worldview. Contrary to the West's belief in the importance of win-win relationships among nations, for Mr. Putin every transaction is win-lose; when one party benefits, the other must lose. For him, attaining, keeping and amassing power is the name of the game.
The only way to counter Mr. Putin's aspirations on Russia's periphery is for the West also to play a strategic long game. That means to take actions that unambiguously demonstrate to Russians that his worldview and goals—and his means of achieving them—over time will dramatically weaken and isolate Russia.
Europe's reliance on Russian oil and gas must be reduced, and truly meaningful economic sanctions must be imposed, knowing there may be costs to the West as well. NATO allies bordering Russia must be militarily strengthened and reinforced with alliance forces; and the economic and cyber vulnerabilities of the Baltic states to Russian actions must be reduced (especially given the number of Russians and Russian-speakers in Estonia and Latvia).
Western investment in Russia should be curtailed; Russia should be expelled from the G-8 and other forums that offer respect and legitimacy; the U.S. defense budget should be restored to the level proposed in the Obama administration's 2014 budget a year ago, and the Pentagon directed to cut overhead drastically, with saved dollars going to enhanced capabilities, such as additional Navy ships; U.S. military withdrawals from Europe should be halted; and the EU should be urged to grant associate agreements with Moldova, Georgia and Ukraine.
So far, however, the Western response has been anemic. Mr. Putin is little influenced by seizure of personal assets of his cronies or the oligarchs, or restrictions on their travel. Unilateral U.S. sanctions, save on Russian banks, will not be effective absent European cooperation. The gap between Western rhetoric and Western actions in response to out-and-out aggression is a yawning chasm. The message seems to be that if Mr. Putin doesn't move troops into eastern Ukraine, the West will impose no further sanctions or costs. De facto, Russia's seizure of Crimea will stand and, except for a handful of Russian officials, business will go on as usual.
No one wants a new Cold War, much less a military confrontation. We want Russia to be a partner, but that is now self-evidently not possible under Mr. Putin's leadership. He has thrown down a gauntlet that is not limited to Crimea or even Ukraine. His actions challenge the entire post-Cold War order including, above all, the right of independent states to align themselves and do business with whomever they choose.
Tacit acceptance of settling old revanchist scores by force is a formula for ongoing crises and potential armed conflict, whether in Europe, Asia or elsewhere. A China behaving with increasing aggressiveness in the East and South China seas, an Iran with nuclear aspirations and interventionist policies in the Middle East, and a volatile and unpredictable North Korea are all watching events in Europe. They have witnessed the fecklessness of the West in Syria. Similar division and weakness in responding to Russia's most recent aggression will, I fear, have dangerous consequences down the road.
Mr. Putin's challenge comes at a most unpropitious time for the West. Europe faces a weak economic recovery and significant economic ties with Russia. The U.S. is emerging from more than a dozen years at war and leaders in both parties face growing isolationism among voters, with the prospect of another major challenge abroad cutting across the current political grain. Crimea and Ukraine are far away, and their importance to Europe and America little understood by the public.
Therefore, the burden of explaining the need to act forcefully falls, as always, on our leaders. As President Franklin D. Roosevelt said, "Government includes the act of formulating a policy" and "persuading, leading, sacrificing, teaching always, because the greatest duty of a statesman is to educate." The aggressive, arrogant actions of Vladimir Putin require from Western leaders strategic thinking, bold leadership and steely resolve—now.
Mr. Gates served as secretary of defense under Presidents George W. Bush and Barack Obama from 2006-11, and as director of central intelligence under President George H.W. Bush from 1991-93.