A standoff between farmers and the Mexican government over the construction of a new international airport is threatening to become a national crisis. The $2.5 billion, six-runway project has irked environmentalists since it was first proposed, because the airport is slated to be built on a former lake bed that is an important nesting ground for birds and is expected to worsen problems of urban sprawl. Environmentalists aren’t the only ones who are upset: Area farmers have taken 15 hostages and are refusing to release them until the airport construction plans are halted. The government has offered the farmers about $3,100 per acre to vacate their land, but the farmers say the price is below market value. The standoff is widely seen as a litmus test for President Vicente Fox, who faces the difficult task of maintaining peace and stimulating economic growth without further alienating environmentalists, social welfare advocates, and the country’s poor.