(It is not surprising that the president of Mexico is shorter than Spain's King Felipe — most people are. Felipe is said to be 197 cm tall, or 6'5". According to Google, President Peña Nieto is 5'8", which is taller than the average Mexican man.)
UPDATE: The video, unfortunately, is no longer available.
The book A Wicked War: Polk, Clay, Lincoln, and the 1846 U.S. Invasion of Mexico by Amy S. Greenberg is available from Amazon.com.