A. The idea came from my editor at Simon & Schuster, Alice Mayhew, who asked me, ``What do you know about the Mexican War?'' I said I knew little but understood that the politics surrounding that war and the expansionist zeal that had captured the country during that time were extremely intense and fascinating. So I embarked on a research initiative and crafted an approach to telling the story. Alice liked it and set me on my course. The result is A COUNTRY OF VAST DESIGNS.