The lesson for all countries should be that invading another country is usually a losing proposition. Just where I live, in the Lake Champlain Valley, armies of France, Britain and the early U.S. marched (or mostly sailed) north and south numerous times during the colonial era and right up through the War of 1812. Only once -- the invasion the ended the French and Indian War -- did the attack succeed. Every other time it failed. Miserably. Invasions are almost always bad ideas.