Well this is a first, Mexico is issuing a warning to their citizens not to visit the US state of Arizona due to the recent passing of the strictest immigration law in history.

You go, Mexico.  It’s extremely rare that Mexico issues a travel advisory for their citizens visiting the States, but with Arizona recently passing one of the most strict immigration measures in U.S. history,  it’s no wonder that Mexican President Felipe Calderón felt obliged to warn his people.

Calderón  warned Mexicans against visiting Arizona, given the newly approved law, which may have a huge impact on tourism in the US state.

Some 24 million Mexicans visit Arizona annually, contributing nearly $2.7 billion to the state’s $18.5 billion tourist industry. On any given day, some 65,000 Mexicans cross the border to work, shop, visit, and inject $7.35 million into the state’s economy. If Mexican citizens were to follow Calderón’s warning in the roughly 90-day span before the law takes effect, Arizona could lose more than $500 million dollars in revenue.

The potential economic fallout from Mexico’s travel advisory is one more marker of the fact that the U.S. desperately needs emerging-market business–and that developing countries know it. Getting slapped with an “instability” warning is the last thing the U.S. needs right now. But as more emerging markets turn sour on America’s leadership potential and its politics, Mexico’s warning may be just the first of many to come.