Your neighbor needs your help. Do you have it in you to lend a hand?

Will you book yourself a week on the beach in Cabo or Puerto Vallarta? You know, for the common good.

This has been a banner decade for empathy tourism; Americans flocked to New York after 9/11 and to New Orleans after Katrina with a sense of public service. Mexico now needs a similar surge.

Our neighbor to the south is having an annus horribilis, as a British monarch might say. These were never going to be good times there, with Mexico's economy so intertwined with ours, but growing concern about drug violence, declining oil prices, and swine flu has further dented brand Mexico.

Adding insult to injury, Washington barred Mexican trucks from entering the United States, and, as of last week, required Americans visiting Mexico to have a passport.

The tourism sector is the largest employer in Mexico and the third-largest source of foreign currency. The swine flu alone is expected to cost the country about $5 billion in tourist revenue (which was already down due to the U.S. recession). Hotel occupancy rates in Cancun in May didn't even reach 30 percent.

The all-clear has been sounded on the virus, but no one knows how long the effect on tourism will last. Mexico's gross domestic product, meanwhile, is expected to contract about 12 percent this quarter.

Why should Americans care? Well, for starters, there is the national security imperative. Say what you will about Mexico - and there is plenty negative to be said - our southern neighbor has been a fairly reliable, stable, and friendly partner for more than half a century, and it is in our interest to keep it that way.

Our nation's political discourse may not always reflect it, but we are blessed to have Canada and Mexico as neighbors. Is there a developing nation of more than 100 million we would rather have on our southern flank? How many other global powers have had the luxury of a long land border that doesn't need to be protected by a standing army?

We have a strong national interest in seeing Mexico, our third-largest trading partner, remain a peaceful, prospering democracy. The resources devoted to cross-border development or security, however, are pitiful compared with aid distributed elsewhere.

But a far more robust commitment to Mexico does assert itself when required, as we saw during the 1990s, when the Clinton White House, bypassing Congress, made about $20 billion in Treasury reserve funds available to Mexico during its last financial crisis. This year, too, Mexico is proving too large to fail from Washington's perspective. The Federal Reserve has made a $30 billion currency swap facility available to Mexico, which gives its central bank privileged access to credit to stabilize the peso.

It would improve the overall health of the relationship, and our ability to think strategically about Mexico's development, if presidents were more transparent about the country's true stake in Mexico, rather than making such commitments on the sly.

That the United States bears some responsibility for Mexico's current woes is another reason to invest in its stability and prosperity. Unlike previous financial crises in Mexico, this one can't be pinned on its macroeconomic sins.

If in the mid-1990s it was fashionable to talk about the "tequila effect" to describe the financial contagion spreading from emerging markets, this crisis is more like a "Budweiser effect," in that Uncle Sam's reckless insistence on living beyond his means caused it. Washington, irresponsibly overleveraged to support an unsustainable standard of living, failed to practice what it preached - to abide by the so-called, um, Washington consensus on economic policy.

Mexico, for its part, has enacted prudent fiscal policies, shored up its foreign reserves, and adhered to the free-trade gospel, continuing to open its economy to foreign goods and investment. The nation also has become a great deal more democratic. Still, despite doing all the right things according to the Washington consensus, Mexico's economy and currency have been harder hit by the Wall Street-triggered crisis than the United States'. No one said life was fair.

Americans also share some of the responsibility for the mayhem unleashed by the showdown between the Mexican state and its rapacious drug cartels, as Secretary of State Hillary Clinton and President Obama were right to point out in recent months. Drug users in this country are underwriting the war in Mexico, and it is being waged largely with guns from this country.

The United States is not about to criminalize guns and legalize drugs to help out Mexico. But you can do your part to help out a good neighbor: Book a trip south. Pronto.

Andres Martinez is a senior fellow at the New America Foundation. This appeared in the Los Angeles Times.