Following the NATO Defense Ministers meeting in Brussels and the annual Munich Security Conference once known as Wehrkinde last week, the debate over whether or not to equip Ukraine with defense armaments such as anti-air and tank missiles is reaching a critical point. On the one hand, Vladimir Putin’s annexation of the Crimea and outright support of Ukrainian separatists against the elected government in Kiev has altered the post-Cold War balance based on respect of borders and territorial integrity.

The Baltic and Balkan states are particularly vulnerable to coercion through what is now called “hybrid war.” Hybrid is a fancy word meaning few holds barred and entails using energy, cyber and propaganda as weapons of intimidation. While NATO’s Article 5 guarantees that an attack against any member is an attack against all, the basis for collective defense was an outright military assault by the Soviet Union. Hybrid is a gray area that is still not fully defined in terms of Article 5 responses.

Certainly, if Russian troops were to cross into NATO territory, the alliance would respond with military means. Shutting off gas and energy supplies is another matter as is launching cyber attacks.

Hence, the case can be made that arming Ukraine with “defensive” weapons is morally and strategically the proper course of action. The underlying assumption is that these weapons will enable the Ukrainian military to impose sufficiently high costs on the Separatists and Russian “volunteers” to deter further aggression and cause Putin to back down. This is a noble argument. But it is sadly flawed and will not work.

Proponents of arming Ukraine are basing their expectations on gradual escalation, that is the cause and effects can be managed and that Russia or the separatists will not raise the ante out of our reach. While those who argue along this line reject the Vietnam analogy, gradual escalation was one of the reasons why the United States failed in that war. Gradual escalation only works when the other side is prepared to yield.

North Vietnam did not back down. What makes anyone think Vladimir Putin will not follow suit and provide even greater support to the Separatists? Ukraine is far more important to Russia than it is to the West, the grounds for protecting territorial integrity withstanding. And adjacent to Russia, geography provides an almost irreversible physical advantage to Moscow.

Put another way, are the West and NATO prepared to go to war to preserve Ukrainian independence? If the answer is yes, then this is not a case of gradual escalation but the commitment to take whatever steps are necessary to keep Ukraine “whole and marginally free.” That must include the option of deploying forces to reinforce Ukraine in its war with the east.

German Chancellor Angela Merkel is in Washington to meet with President Barack Obama on this crisis. Many Europeans are opposed to providing even defensive arguments to Ukraine because of the fear that Putin will out-escalate these actions. They are right.

Meanwhile, many in the US and especially in Congress prefer taking the moral high ground believing that underdog Ukraine needs to be given the means to turn this into a fair fight. Sadly, however appealing, that argument will not work unless Putin surrenders. That is not a good bet.

What to do? Further sanctions including cutting Russia off from the SWIFT banking system have sparked threats of retaliation on the grounds that such denial would constitute grounds for war. And here, while NATO has a powerful conventional military advantage over Russia, Moscow has an order of magnitude numerical advantage in short range, tactical nuclear weapons.

If sanctions led to a greater confrontation, what happens if Moscow begins using its nuclear muscle to intimidate NATO? And, as a side note, one can speculate that Putin would welcome a nuclear crisis that might indeed lead to an explosion in oil prices favoring Russia.

The most sensible solution since covert arming of Ukraine is no longer feasible and will leak is to reinforce NATO more dramatically. Unfortunately that should have been done at the September NATO summit in Wales. A “porcupine” strategy for the flanks is one option in which anti-air and tank missiles and other defensive systems are sent to the Baltics and Balkans in large numbers as a deterrent to Russia and reminiscent of the 1939 Winter War in which tiny Finland gave the Soviet Union a very bloody nose.

For negotiations to succeed, they must be based on recognition of Russian annexation of Crimea in exchange for assuring Ukrainian territorial integrity probably with greater autonomy for the east. This is not ideal and perhaps the least bad outcome. Unfortunately, as we should have learned from Vietnam, gradual escalation is a formula for failure. Let us not repeat that failure in Ukraine despite the fatal attraction of the argument for providing defensive weapons to even the fight.

Dr. Harlan Ullman is Senior Advisor at the Atlantic Council and Business Executives for National Security. His latest book is “A Handful of Bullets: How The Murder of Archduke Franz Ferdinand Still Menaces the Peace.”