The American Civil War limits Washington's immediate ability to act in Mexico. Other European powers would broadly accept the imperial project if they received the money owed to them. They also have wars and political problems of their own, so North American events do not determine every government's priorities. The proposed empire needs to settle the Mexican struggle before the United States becomes free to intervene more actively. The scenario sets a practical window of April 1864 to May 1865, described as a little under thirteen months.
Notable Point · 51:25-53:00
The American Civil War sets a short window for victory
The scenario gives Maximilian roughly thirteen months to settle the conflict before American attention returns to Mexico.