Darko Vojinovic, Associated Press
A man holds a banner that reads: "Boycott Illegal Referendum!" during a rally against the breakup of the country Simferopol, Crimea, Ukraine, Tuesday, March 11, 2014. The Crimean parliament voted Tuesday that the Black Sea peninsula will declare itself an independent state if its residents agree to split off from Ukraine and join Russia in a referendum.

For those of us interested in the lessons of history (because we don’t want to be doomed to repeat them), Crimea is best known for the 1850s Crimean War when the Russian Empire fought the Western powers (including the British and the French) over land grabs by those powers. Once again, Crimea has become a battleground involving new protagonists against Russia — the United States and the European Union.

For nearly all of the past 330 years, Crimea has been part of Russia. Prior to the past quarter century, with the exception of brief periods in the 17th century and the early 20th century, Crimea was territory of the Russian Empire and the Soviet Union. But when Ukraine declared its independence from the Soviet Union in 1991, Crimea went with the rest of Ukraine and left Russia. And 54 percent of citizens of Crimea supported that declaration.

Nevertheless, Russian President Vladmir Putin seems determined to bring it back. He has said that the breakup of the Soviet Union was a “major geopolitical disaster” because it left tens of millions of Russian citizens outside Russian territory. Actually, the Soviet government worked hard to create that very situation. During Joseph Stalin’s regime, the Soviet government resettled millions of its citizens by moving Russian speakers to non-Russian areas for work projects and deporting non-Russian speakers to Russian territory to eliminate potential threats to the state. Moreover, forced use of Russian (along with prohibition of non-Russian languages and cultures) furthered “Russification” of areas such as Georgia, Ukraine and the Baltic Republics.

Like Adolph Hitler’s claim regarding German speakers in the 1930s, Putin’s assertion is that he holds an obligation to protect Russian speakers who are citizens of other nations. He is using the pretext that the new government in Ukraine is threatening Russian speakers in Crimea and that the new leaders in Ukraine are illegitimate. (The real reason is those new leaders, who are pro-European Union, toppled a president who was pro-Russian.)

Putin has dispersed Russian troops from their bases in Crimea to take over strategic military targets and surround Ukranian military installations. The Russian parliament, controlled by Putin, has voted to annex Crimea.

Western nations have a momentous decision ahead of them. Should Russia be stopped in its effort to take Crimea back? The answer is an unqualified yes. Vladimir Putin is willing to test the fences to see how much the West cares about his efforts to restore Russian territory or at least create puppet states. How the West responds will determine what fences really exist.

Putin has done this before, successfully. Russia waged war with Georgia in August 2008 over South Ossetia, a separatist region of Georgia that sought independence from Georgia under Russia’s protection. As with Ukraine, Putin declared military intervention in Georgia was necessary to protect Russian speakers there. After the war, Russia maintained several thousand troops on a set of military bases in two regions of Georgia, despite protests from the British and French governments. Words alone did not prevent Russia from declaring the region independent from Georgia, providing Russian citizenship to the citizens there, and continuing its military presence.

In essence, the West’s signal was acceptance of Russian military domination of that region of Georgia. Putin may well expect the same outcome. He should not get it.

What should the West do? Actions, not words, must be taken to punish Russia for violating Ukraine’s sovereignty. The West should freeze assets, postpone investment in Russia, and, if necessary, institute full-scale economic sanctions on trade with Russia. And the West should call on Russia to postpone the hastily called referendum on annexation while Russian troops occupy Crimea. Such a referendum should be held, but only after the citizens of Crimea and Ukraine can work through the implications of such action. By contrast, the Scottish referendum on independence to be held this September has been scheduled since last December, thus allowing time for extensive public debate.

If the West does not act more decisively this time, Putin will do the same thing again in the future. Then, we truly will be doomed to repeat the mistakes of history we have not learned.

Richard Davis is a professor of political science at Brigham Young University. His opinions do not necessarily reflect those of BYU.