Ukraine must wish it had kept its nukes

The world seems to have forgotten that Ukraine began its independence from the Soviet Union in 1991 as a major nuclear power, possessing the world's third largest nuclear force, more powerful than Chinese, British and French forces combined. That capability gave Ukraine great foreign policy leverage with Russia and other countries.

No doubt, Ukraine probably wishes that leverage was still available today to resist the aggression of Russian President Vladimir Putin.

However, promptly persuading Ukraine to give up its nuclear weapons capability was a major foreign policy objective of the United States, Britain, France and Russia. As a result of pressure from those countries, Ukraine gave up its nuclear power by 1996 -- but with a significant precondition. Ukraine obtained an unprecedented set of security guarantees from these countries, which were memorialized in the Budapest Memorandum. The declaration committed Russia, Britain and the U.S. to respect Ukraine's borders, abstain from the use of force against Ukraine, and forego economic coercion. Even China and France, while not signing the declaration, sent diplomatic notes expressing their support.

Thus, Russia's current military actions in Crimea, coupled with an anemic Western response, will deal a grave blow to international law in general and nuclear non-proliferation in particular. These actions lend credence to the idea that the possession of nuclear weapons, more so than the security guarantees by even all of the great powers, is a reliable deterrent to international aggression.

Had Ukraine still had its 1,800 nuclear warheads, Russia wouldn't have launched its invasion of Crimea. This fact will not be lost on any aspiring nuclear state, be they rogues such as Iran, or pro-Western countries such as Japan, and could undermine the cause of nuclear non-proliferation.

While bilateral and multilateral security guarantees are quite common, a joint commitment affirmed by the greatest powers, is rare. To find an equally important pre-Budapest example, one would have to go back to the 1839 Treaty of London, in which great European powers guaranteed Belgium's territorial integrity and independence. After more than 70 years, the treaty was violated by Germany in the opening days of World War I, and Britain fulfilled its obligations by declaring war on Germany.

While going to war with Russia over Ukraine is unthinkable, the U.S., Britain, France and Germany should at least mitigate the damage to the cause of non-proliferation and international law by imposing the most robust set of economic, financial and diplomatic sanctions on Moscow.