From Sweden in the Baltic to Tartus in the Mediterranean, Russian forces are on the offensive. The consensus among U.S. officials not beholden to the White House is that Mitt Romney was right. Vladimir Putin’s Russia is the most dangerous threat to America.

And not only to America: Russia’s attempts to reclaim its empire spread conflict and misery, prolong war, destabilize the postwar alliance system that has brought security and prosperity to the world, and erode Western values such as freedom, equality, and individualism. Though Russia may no longer espouse global communist revolution, the consequences of its militarism and aggression are not limited to a small geographic area. The Comintern is gone. But the goals of dominating the Eurasian heartland, Finlandizing Europe, and isolating and challenging the United States have returned. The stronger Putin becomes, the more despotic, poorer, and more corrupt is the world.

Except for sanctions imposed after Russia’s invasion of Ukraine and the occasional scolding, President Obama has been uninterested in retaliating against imperialism and deterring further aggression. He holds the view that history will expose Putin as a pretender and fool, and that Russia will be bogged down in a Syrian quagmire just as it was bogged down in Afghanistan long ago. What Obama forgets is that the Soviet Union’s defeat in Afghanistan came about because the United States financed and equipped anti-Soviet forces—a course of action he has rejected since the Syrian uprising began in 2011.

Obama’s supporters note that there is no clear U.S. ally in the Syrian conflict. Obviously not, since the president did nothing to identify and assist potentially friendly anti-regime Sunnis when the war began. Nor has he aided fully those few groups—"Syrian Kurds close to Turkey, moderate forces supported by Jordan close to its border, and small number of other moderate Syrians"—that, at least rhetorically, the United States backs today.

Obama’s critics, meanwhile, are concerned with tactics. Both Hillary Clinton and Marco Rubio have called for America to impose a no-fly zone over Syria. They’re several years too late. A no-fly zone might have worked at the beginning of the conflict, as part of a strategy of coercive diplomacy to remove Bashar al-Assad and reach some sort of power-sharing agreement among Syrian tribes. Now, with Su-25s flying unrestricted over Syria, a no-fly zone would be greeted by the Russians as a nonstarter.

Worse, it would invite direct confrontation with the Russians, who are already buzzing NATO airspace from their new southern flank. Putin would like nothing more than to humiliate America over the skies of Raqqah. A no-fly zone is also superfluous. Our forces are already operating above parts of Syria—we could establish safe-havens at any time without asking for Russian permission. The problem isn’t our capabilities. It’s our lack of will.

What to do? The time has come for a revised strategy towards Russia, the greatest military and ideological threat to the United States and to the world order it has built over decades as guarantor of international security. We’ve faced a similar problem before. To create a freer and richer world, not the United States but Russia must be knocked back on its heels.

That is exactly what Ronald Reagan did in the final years of the Cold War. What is required today is a Reagan Doctrine for the twenty-first century—a comprehensive military, diplomatic, and cultural approach that elevates America’s stature and diminishes Russia’s.

I can hear liberals already: Reagan, they’ll say, was not a warrior but a peacemaker. Didn’t he negotiate with Gorbachev, didn’t he offer at Reykjavik to eliminate all ICBMs in exchange for the right of strategic defense? And so he did. But to focus only on Reagan’s diplomacy is to suffer from historical myopia. It is to ignore Reagan’s first term in favor of his second.

The hawkish policies Reagan enacted between 1981 and 1985 gave him the economic, political, and military leverage to become friends with Gorbachev later. And only with Gorbachev: During Reagan’s first term, three Soviet leaders preceded the author of glasnost and perestroika. The president didn’t meet with any of them. "They keep dying on me," he liked to say.

In their moral disapproval of force, in their fallacious belief that human beings of every nation and every government share the same values and interests, liberals forget that every diplomatic solution is based on the balance or preponderance of military power. It is the weaker party that seeks negotiations—just as Europe and the United States, consumed by wars in Iraq and Afghanistan, did after Russia’s invasion of Georgia. Just as President Obama, preoccupied with ending the Middle Eastern wars and resolving the financial crisis, attempted his reset with Russia. Just as Europe and the United States, in the grip of anomie and malaise, have sought to freeze the conflict in Ukraine and "de-conflict" the escalating war in Syria.

Let’s reverse the equation.

Like the strategy pursued by our fortieth president more than 30 years ago, a twenty-first-century Reagan Doctrine would have three parts:

Military buildup. President Reagan reversed the degradation and demoralization of the U.S. armed forces. The defense budget in his first term more than doubled. Yes, there was waste. But more important than the $400 toilet seat were the B1 bomber, the stealth fighter, the Trident submarine, and hundreds of F-14s and F-15s. Defense spending created jobs, inspired patriotism, and laid the foundation for American success in Operation Desert Storm and the Balkan wars. We use many of these platforms to this day.

The gusher of weapons scared our enemies. "The scale and pace of the American buildup under Reagan," writes Henry Kissinger in Diplomacy, "reinforced all the doubts already in the minds of the Soviet leadership as a result of debacles in Afghanistan and Africa, about whether they could afford the arms race economically and—even more important—whether they could sustain it technologically."

Who now holds such doubts? The trajectory of U.S. troop numbers and defense budgets is downward. The "sequester" is about to take a huge bite of the Pentagon’s resources. Our ability to fight in two theaters at once, a pillar of postwar American defense policy, is in doubt.

"Just as the threats have become visible and undeniable," write the authors of "To Rebuild America’s Military," a new American Enterprise Institute report, "the United States is continuing to cut the armed forces dramatically, having imposed the cuts through an extraordinary means—a law imposing arbitrary limits on parts of the federal budget and employing the mindless tool of sequestration—with no analysis whatsoever of the impact on the nation’s security."

The AEI scholars recommend a return to the level of defense spending proposed by Robert Gates, and the gradual build to "an affordable floor of 4 percent of gross domestic product that would sustain the kind of military America needs." These numbers might not be as shocking as Reagan’s. But at least they would reverse the hollowing out of the force. And they would grab the attention of the Kremlin.

Both left and right are likely to oppose more spending on the grounds of debt and deficits. For the left to make this critique is disingenuous—their leading economists say deficits do not matter in the current economic environment and call for an expansionary fiscal policy. What the right needs to understand is that deficit reduction and balanced budgets are worthy goals in a time of peace. And peacetime this is not.

Strategic Weapons. Vladimir Putin plays ICBM politics. His regime holds nuclear retaliation as its ultimate trump in negotiations—and while the Russians have not played this card, oh how they love to show it.

The U.S. response is naïve. Not to mention contradictory. It combines idealistic calls for nuclear abolition with hapless and toothless diplomacy that does little to stop Iran from spinning centrifuges, North Korea from building more bombs, and Russia from violating treaty commitments.

We forget we hold nuclear cards, too. This is a fact Reagan did not lose sight of. "The two strategic decisions which contributed most to ending the Cold War," writes Kissinger, "were NATO’s deployment of American intermediate-range missiles in Europe and the American commitment to the Strategic Defense Initiative (SDI)."

Keep the Pershing IIs on hold (for now). But please update and modernize our nuclear forces, which exist in an embarrassing state of disrepair and neglect. And do not forget the importance of strategic defense: Development of anti-ballistic missile technologies would be a highly controversial, and highly important, part of any renewed defense buildup. The broadening of the missile shield reassures allies—and worries Russia.

Not only would a revitalized and advanced nuclear force, coupled with increased funding and enlargement of strategic defense, assert U.S. supremacy, deter adversaries, and develop innovative technologies. It would also bring political benefits to whoever proposed it.

When Reagan announced SDI in the spring of 1983, notes Kissinger, "The experts had all the technical arguments on their side, but Reagan had got hold of an elemental political truth: In a world of nuclear weapons, leaders who make no effort to protect their peoples against accident, mad opponents, nuclear proliferation, and a whole host of other foreseeable dangers invite the opprobrium of posterity if disaster ever does occur."

The president’s duty is to ensure that it does not—not by terrorists who desire weapons of mass destruction, not by the states that possess them.

Insurgency. It was Charles Krauthammer who coined the phrase "Reagan Doctrine" in an April 1985 essay for Time magazine. The article described Reagan’s support for anticommunist forces in Nicaragua, Angola, Afghanistan, and beyond. Some of those forces, like Solidarity in Poland, truly were democratic. Others, like the mujahedin, were the enemies of our enemy—and thus, in specific circumstances, worthy of our help.

It takes a set of moral blinders the size of the president’s ego not to recognize today’s Russia as America’s enemy. There is no other power as devoted to undermining U.S. authority and prestige and interests—from subverting the NATO alliance to replacing us as the dominant external power in the Middle East to hacking our technological infrastructure to harboring the fugitive Edward Snowden. As America has waned, Putin has waxed. And so for America to wax, Putin must wane.

We must arm his enemies. That means deadly weapons and massive financial aid to Ukraine. Forward bases in the Baltics. And the sending of arms and cash to the Syrian rebels his jets are strafing. Not even the liberal Vox.com pretends that Putin is going after ISIS; why should our government?

Imposing costs on Putin requires dealing with unsavory people. It risks unforeseen consequences, some potentially negative. But the actual consequences of the policy being pursued at the moment—ongoing war, regional destabilization, humanitarian chaos, Islamic radicalization, and erosion of U.S. leadership and credibility—are worse.

The insurgency launched by Reagan was not limited to arms. It also had an ideological component. "The Reagan Doctrine has been widely understood to mean only support for anticommunist guerillas fighting pro-Soviet regimes, but from the first the doctrine had a broader meaning. Support for anticommunist guerillas was the logical outgrowth, not the origin, of a policy of supporting democratic reform or revolution everywhere, in countries ruled by right-wing dictators as well as by communist parties," says Robert Kagan in A Twilight Struggle.

Speaking forthrightly and proudly of liberal values, and condemning their abuse within the Russian sphere of influence, is a requirement of any foreign policy associated with Ronald Reagan. As Secretary of State George Shultz put it in 1985: "The forces of democracy around the world merit our standing with them. To abandon them would be a shameful betrayal—a betrayal not only of brave men and women but of our highest ideals."

Standing with the forces of democracy is not the same as calling for elections everywhere. Elections are not the beginning of the policy. They are its endpoint. The beginning is in the rhetorical promotion of individual freedoms, in renewed financial support for nongovernmental organizations promoting civil society and an independent media, in education in the habits and traditions of the West.

The Kremlin spends hundreds of millions of dollars each year on a global propaganda network that spreads conspiracy theories, distorts reality, and incites suspicion and hatred of the United States and its representative democracy. And that is just Russia—China and Qatar have similar operations. We have nothing that bears comparison. The main Putin network, RT, has more employees than the Voice of America. We are disarming ourselves not only materially but also ideologically. This must end.

The agenda I have outlined would cost quite a bit of money. It would involve America with some morally suspect individuals. The debate over it would be heated. There would be reprisals.

But the Reagan Doctrine was all of those things, too. And it worked. "The Reagan Doctrine proclaims overt and unashamed American support for anti-Communist revolution," Krauthammer wrote in 1985. "The grounds are justice, necessity, and democratic tradition." Replace anti-Communist with anti-authoritarian, and what has changed? If we are to reestablish American ideals, American interests, and American pride, we must hurt the bad guys, and overtly and unashamedly revise the Reagan Doctrine for a new American century.

Putin? He is one bad guy. So let’s take off our gloves.