Complex sentence: The P.1154 was a winner of the NATO competition and prototype construction was already underway at the point of cancellation in 1965, the result of the French government withdrawing shortly after its selection over the Dassault Mirage IIIV.
Split into simpler sentences: The P.1154 was a winner of the NATO competition and prototype construction was already underway at the point of cancellation in 1965. The French government withdrew shortly after its selection over the Dassault Mirage IIIV.