Are you talking about the entirety of American history. Assuming you are due to the Mexican American war, there are a few examples: 1. The United Kingdom, and

Are you talking about the entirety of American history. Assuming you are due to the Mexican American war, there are a few examples: 1. The United Kingdom, and thus Canada, during the War of 1812. 2. Germany in World War I, via the Zimmermann telegram. Although rejected by the Mexican government, the threat was absolutely credible. 3. The Barbary Pirates. Protecting American shipping interests is protecting the country as well, as well as an attack on American territory. 4. Iran during the Iranian hostage crisis. Again, attacks on an embassy/diplomatic mission constitute an attack on sovereignty, especially when those attacks are directed against Americans.