"This is how the Mexican Empire will perish, a creation based on the assumption of a southern triumph and which today finds itself singularly compromised by the opposite result. Even with a president less democratic than Mr. Johnson, the United States would never have tolerated the establishment at its gates of an absolute monarchy under the rule of a foreign dynasty. The misfortunes of the civil war did not allow them to oppose it when the facts were unfolding. Perhaps in order to avoid a war with France they will not attack the new order of things directly, but certainly they would do nothing to support it, and the disbandment of their armies will provide them with all the desirable means to overthrow it indirectly."
January 1, 1970
https://en.wikiquote.org/wiki/Maximilian_I_of_Mexico