By 5 September, Allied forces had been in continuous retreat for two weeks and were close to exhaustion. The advancing German army appeared poised to encircle Paris. With a last vestige of the ‘offensive spirit’ symbolized by the defunct Plan XVII, Marshal Joffre resolved to counterattack, dragooning the support of the British General French. On 6 September, the French 6th Army attacked the right flank of the German 1st Army, which promptly wheeled round to rebuff the strike. It was then that Allied air reconnaissance revealed that 30-mile gap had opened up between the two German armies, and the British Expeditionary Force and French 5th Army were promptly ‘sent into the breech’. General von Kluck, commander of the 1st Army, decided to resolve the impasse by routing the French 6th, but emergency reserves, rushed in from Paris (many transported by taxis), saved the day.