If we have a "responsibility to protect" the people of Libya, who are dying by the thousands, how can that same responsibility not apply to our southern neighbor, where the war between the drug lords and the government has killed nearly 40,000 people and is even producing mass graves? Last week, in El Paso, Texas, President Obama tried to appeal to Hispanics by addressing issues like America’s porous borders and his sympathies for Mexicans who come here in search of work. But his concern stopped at the border. The carnage in Mexico, including most prominently just a few miles south of the border, merited not one presidential word. But only last week more remains were uncovered in a mass grave at the Mexican state of Durango, bringing the total there to 218 dumped bodies and surpassing Tamaulipas state, where "only" 183 bodies were found in mass graves last month. Last week, Mexico’s federal government announced the capture of top leaders of the country’s most powerful gang, known as the Sinaloa Cartel. So now local authorities at Culiacan, the capital of Sinaloa state, are bracing for a major escalation in killings. That’s what always follows the arrest of major narcobosses. Mexico’s war, which President Felipe Calderon unleashed shortly after his inauguration in December 2006, exacts 300 drug-related deaths a week, complete with grotesque hangings, mass graves and more gore than a Quentin Tarantino movie. Angry Mexicans are taking to the streets. Last Sunday, thousands marched peacefully on the capital, demanding that officials overseeing the drug war be sacked. Many also blame us. The gangs finance their atrocities with gobs of cash they gain due to our insatiable appetite for substances that we’ve outlawed but consume liberally. So what is our duty? In March, Obama declared, "When our interests and values are at stake, we have a responsibility to act." But that, of course, was about Libya, where he invoked the elusive "Responsibility to Protect" concept. R2P, as it’s known in United Nations-ese, was popularized during the last decade by then-UN Secretary-General Kofi Annan. It became a pet phrase for globalists who believe (wrongly) that the "international community" has the wherewithal to address genocide and other war atrocities. As we see in Libya, such communal efforts are mostly marked by inefficiency and wobbly decision-making, which bode ill for any war effort. Although R2P doesn’t make such distinctions, its interventionist ways should never apply to democracies like Mexico, where a legitimately elected leader has willingly opted to poke a hornet’s nest, thinking it will make his country a better place. But we’re deeply involved in this losing war, so we must do something. But what? America has three options, says former Mexican Foreign Minister Jorge Castañeda, whose new book, "Mañana Forever? Mexico and the Mexicans," hits US stores next week. We can do "a little more of the same": Send Calderon a little more cash; help him a bit more with intelligence and hardware. This is the option we’ll likely go for, Castañeda says, but it surely won’t end the killing. Or we can opt for "a whole lot more": On one hand, make a major effort to reduce America’s demand for drugs; on the other, send south a lot more money, hardware and advisers. It might work, but it won’t happen; Casteñeda is diplomatic in saying "probably not." Then, he says, we might want to look into the "least realistic but best" option: Work with Mexico, Colombia and other Latin American allies to "throw away the strategy of prohibition." In the long run, he believes, this approach will be adopted anyway. (Full disclosure: Castañeda is my cousin.) What we can’t do is ignore Mexico’s carnage. Yes, immigration is a mess. Democrats scream racism, and Republicans preach law, but to date neither party has come up with comprehensive legislation that would satisfy our labor needs while allowing industrious Mexicans to find employment here. Obama’s El Paso speech only deepened the partisan bickering, delaying any reform until at least 2013. But as bad as it is, we can tolerate the stream of migrants who’ll likely continue to enter America. Can we really tolerate mass killing on our nation’s doorstep — which may soon cross north and for which we bear some responsibility?