During the May Crisis of 1938, on 21 May, Bonnet advised Lord Halifax that Britain should warn Berlin that if the Germans attacked Czechoslovakia, then Britain would become involved in the ensuing war, only to be informed that London had already delivered such a warning. In a talk with the British Ambassador, Sir Eric Phipps, Bonnet attacked Beneš for ordering Czechoslovak mobilization without informing France first and criticized Prague's for its "hasty action", but at a meeting with the Czechoslovak Minister to Paris, Štefan Osuský, on 21 May, Bonnet did not criticize Prague in violation of his promises to Phipps. Phipps urged Bonnet to use the crisis as an excuse to renounce the Franco-Czechoslovak alliance of 1924, but Bonnet refused unless France could secure a stronger commitment from Britain to come to France's aid in the event of war with Germany.