The Trump administration announced on Friday that it would allow the sale of advanced armed drones to other nations and bypass part of an international weapons export control agreement that the United States helped forge more than three decades ago. Administration officials have debated for years how to sell the armed drones despite clauses in the agreement, known as the Missile Technology Control Regime, that prevent its 35 members from doing so. The administration announced in 2018 that it was expanding drone sales, but has not been able to do so because of the limits set by the deal. The agreement is not legally binding and is treated as an understanding among its member nations. But circumventing one part of the pact could undermine the agreement in general and encourage other nations to selectively ignore or reinterpret clauses that they find inconvenient.