OMG!...how could you miss this
from your own link?!
2007 Update The Departments of State and Homeland Security require citizens of the United States, Canada, Mexico, and Bermuda to present a passport to enter the United States when arriving by air from any part of the Western Hemisphere as of January 23, 2007.
A separate proposed rule addressing land and sea travel will be published at a later date proposing specific requirements for travelers entering the United States through land and sea border crossings. As early as January 1, 2008, U.S. citizens traveling between the United States and Canada, Mexico, Central and South America, the Caribbean, and Bermuda by land or sea could be required to present a valid U.S. passport or other documents as determined by the Department of Homeland Security.
How about something better than wiki.answers.com as a source?
Canada http://travel.state.gov/travel/cis_pa_tw/cis/cis_1082.html
When returning to the United States from Canada, it is very important to note that all U.S. citizens are required to present a valid U.S. passport to enter or re-enter the United States via air. For entry into the United States via land and sea borders, U.S. citizens must present either a U.S. passport, passport card, NEXUS card, Enhanced Drivers License, or other Western Hemisphere Travel Initiative (WHTI)-compliant document.
Answer is NO you do not need a passport.
Answer is, you do need a passport or some other authorized ID!
Nothing about a military ID, is there.