From Longman Dictionary of Contemporary Englishwith/at a stroke of the penwith/at a stroke of the penSIGN YOUR NAMEif someone in authority does something with a stroke of the pen, they sign an official document to make a decision with important and serious results He had the power to order troops home with a stroke of his pen. → stroke
Examples from the Corpus
with/at a stroke of the pen• With a stroke of the pen, the two leaders have cut the number of nuclear weapons in half. 