Standing alongside his Mexican counterpart Felipe Calderon, US president Barack Obama has promised to help him in what he called his “courageous” fight against the drug cartels.The war against drugs was the main theme of Obama’s trip to Mexico – his first to Latin America as president. The problem of the flow of US arms over the border to Mexico and immigration were also top of the agenda. Most of the US’s 12 million illegal immigrants come from Mexico. “My country has been greatly enriched by migration from Mexico,” said Obama. “Mexican-Americans form a critical and enduring link between our nations. And I am committed to fixing our broken immigration system in a way that upholds our traditions as a nation of laws, but also as a nation of immigrants.” In an unprecedented move, President Obama has acknowledged that America shares the blame in Mexico’s drug problem as its biggest client. He has been pushing the Senate to ratify a treaty designed to reduce the flow of arms and ammunition to the Latin American cartels that supply cocaine and marijuana to US users. Last year, violence between drug cartels fighting for control of the market claimed more than 5,000 lives in Mexico.