Russia's interest in South America should alert the U.S.

Russian President Dmitry Medvedev's four-nation jaunt through Latin America, which started at an international summit in Peru on Saturday and finishes in Cuba on Thursday, might be thought of as his badwill tour -- not aimed at Latin America, but a country just north of Mexico.

Medvedev will clasp arms with Venezuelan President Hugo Chavez today even as a small flotilla of Russian warships conducts training exercises alongside the Venezuelan navy, the first time since the end of the Cold War that Russian ships have trained in the Caribbean. Chavez, who has built his political career on baiting the United States, will announce new arms and energy deals with Russia, including a scary proposal for the two countries to cooperate on Venezuela's first nuclear power plant. Then Medvedev will try to invoke the ghost of missile crises past by heading to Havana, where he'll seek to restore Soviet-era ties that were severely damaged when Moscow stopped propping up the island's economy.

For the Kremlin, this is about sending a message to Washington: If you trespass in our backyard, we'll trespass in yours. Medvedev and his puppeteer, Russian Prime Minister Vladimir V. Putin, are furious at U.S. intentions to build a missile shield in Eastern Europe, as well as Washington's support of NATO membership for former Soviet satellites, its objections to Russia's attacks in Georgia this summer and its backing of Kosovo's independence.

There's no sign that the Bush administration is taking the saber-rattling seriously, nor should President-elect Barack Obama. The Russian navy is less a threat to the U.S. than it is to its own sailors, who have a frightening tendency to die in accidents like the sinking of the Kursk nuclear submarine in 2000; the flagship of the forces training in the Caribbean, a cruiser called Peter the Great, was said in 2004 by Russia's naval commander to be in such bad condition that it could explode at any moment.

Yet Medvedev's visit does bring up an issue that should concern Obama. Russia isn't the only country casting covetous eyes on Latin America's resources, goods and consumers. Chinese President Hu Jintao also toured the continent last week to drum up business, which is booming: China's trade with Latin America jumped from $10 billion in 2000 to $103 billion in 2007. Obama has rightly signaled that he may ease the U.S. trade embargo with Cuba, yet he has also expressed skepticism at the Colombia free-trade pact and even the North American Free Trade Agreement. If the U.S. snubs its trading partners in Latin America, it would leave a vacuum that countries like Russia and China would be only too happy to fill -- to the detriment of both our economy and national security.