Alliances, Coalitions, and Ententes - Jeffersonian realism
Thomas Jefferson obviously understood the difference between artificial and natural connections with Europe. His condemnation of "entangling" alliances referred to involvements in European politics, not to the defense of American interests. When, in 1802, France seemed about to occupy the Louisiana Territory, striking a wedge between the United States and land that many Americans assumed was destined to become part of the United States, Jefferson's thoughts turned to plans of alliance with Great Britain. The Louisiana Purchase made that unnecessary, and Jefferson then followed policies that subtly favored France in its conflict with the British. His reasoning was simple and logical: only the English had a fleet large enough to pose a military threat to the United States, and, hence, they were America's only potential enemy of substance. But none of his talk of alliance or his attempts to play at a timid and small form of alliance politics came to public attention. With "no entangling alliances" already a tradition, domestic political considerations made Jefferson keep such thoughts to himself and his closest advisers.
After a brief period of peace beginning with the Treaty of Amiens (1802), the Napoleonic wars started anew in 1803. Again the United States found itself caught between two great powers. As both England and France turned increasingly to economic warfare, American attempts to maintain business as usual were less and less successful. Frustrated in his attempts to negotiate arrangements that would permit American foreign trade to continue without harassment, Jefferson overestimated the value of that trade to the European powers and also turned to economic coercion. An embargo prevented all American ships from sailing to foreign destinations but drove home the lesson of America's economic dependence upon trade with Europe—a lesson statesmen have never forgotten.