The United States is the only country with a B-2 Spirit stealth bomber for several reasons, including the extraordinarily high cost, advanced technology, and the strategic military advantages it provides. Let's break down these factors: 1. Development and Production Costs: - The B-2 Spirit program was one of the most expensive military projects in history. The unit cost of a B-2 is around $979 million in 1997 dollars, but when you factor in the program costs, facilities, spare parts, etc., the total cost per aircraft reaches approximately $2.1 billion. Such enormous expenditure is prohibitive for most countries. 2. Operational and Maintenance Costs: - The B-2 costs between $135,000 to $163,000 per flight hour in maintenance. This includes 60 man-hours of maintenance for each hour of flight. The ongoing operational costs add another layer of financial challenge, making it difficult for countries to sustain operations even if they could afford the in...