By now virtually all Western policy makers and analysts agree that Vladimir Putin is pursuing a neo-Czarist policy. Like the Czars in the eighteenth and nineteenth centuries, and, for that matter, like the United States, Putin is slowly expanding his country’s borders, exploiting his neighbor’s weaknesses and responding to call for support from his ethnic confreres in those countries. For Russia in the nineteenth century it was central Asia and the Caucasus; for the United States during the same period it was California, the Southwest, and Texas. Putin can argue that if Washington could invade and overthrow governments at will—Iraq being the most recent example, but Panama and Grenada not all that long ago—he can do the same. And he might add that if the West can support the separatist Kosovars, ignoring the territorial integrity of Serbia, he can do the same in Ukraine.

There is no point in trying to split hairs to demonstrate that somehow what the United States, or the West in general, does is “different;” that Washington and its allies no longer absorb the countries they attack. Putin is not a lawyer, nor is he interested in legal casuistry. The only thing he will understand, as did his Czarist predecessors, is strength at a minimum, force at the maximum. If he sees that the cost of appropriating his neighbors’ territories runs the risk of being too high, he will stop, and do so abruptly.

And therein lies the problem. Whereas Putin is no Hitler, the West is full of Chamberlains. Putin may not tolerate gays, but neither do many other non-Western states. Putin has not persecuted other minorities—Jews have it better in Russia now than in the past thousand years. There is still an opposition; there are no concentration camps. On the other hand, apart from his usual lofty rhetoric, President Obama has yet to lower the economic boom on Russia. And the EU, for all its own bluster, is divided among its member states as to how to react, or whether even to react at all.

Putin rightly senses weakness, not only the part of Europe—long the weak reed in the Western alliance—but on the part of Washington as well. He has watched the Obama administration go from “leading from behind” to not leading at all. When the president speaks of crossing a line, Putin wonders whether that is the same line that Assad was not supposed to cross. Having tested Washington with respect to Syria, supporting a ghoulish regime that has long been condemned by the West and suffering no consequences from doing so, Putin has no qualms about tearing Ukraine shreds. And he can tell himself that what he is doing is no different from America’s incursions into Mexican territory from the “halls of Montezuma” to the Wilson administration’s operations against Pancho Villa about a century ago, which for Russians is but the day before yesterday.

Vladimir Putin has the support of the ethnic Russians in eastern Ukraine who share neither language nor religion with their counterparts in the western part of that country. He can make the case that they deserve even more autonomy than they already receive; after all, the Scots, the Catalans and others seek at least the same if not more. But neither the Scots nor the Catalans are planning to immerse themselves in another country; nor are any of Britain or Spain’s neighbors planning an invasion on behalf of those peoples. The West should be prepared to push Kiev into granting even more autonomy to its eastern regions; at the same time, Washington and its allies must do more than utter fine phrases in order to incentivize Russia to withdraw its forces from Ukraine.

Sanctions would be a good start—they can always be lifted once Russia withdraws its forces. But the real way to show Putin that the West means business is for it to discard the restraints that Washington in particular has placed on defense spending. The administration should immediately issue a budget amendment that increases defense spending by at least $25 billion; doing so would send Putin a message that his gamble on American passivity has misfired, and that sequestration is not Russia’s best friend. Only then will the Russian strongman finally recognize that should America deploy its naval forces to the Black Sea, as well it should, Washington is not merely showing force, but is prepared to use it to defend the sovereignty of a beleaguered nation, as it did, so successfully, on behalf of tiny Kuwait nearly twenty-five years ago.

Dov Zakheim served as the undersecretary of defense (comptroller) and chief financial officer for the U.S. Department of Defense from 2001–2004 and as the deputy undersecretary of defense (planning and resources) from 1985-1987. He also served as DoD's civilian coordinator for Afghan reconstruction from 2002–2004. He is a member ofThe National Interest's advisory council.