Nor did the British have the slightest idea of attacking Germany, even though they continue to bluff in the hope that Hitler will resign. The Royal Air Force would not be used against German units to support a French offensive, and airstrikes in Germany would be limited to clearly marked military installations (an unenforceable proposal, then as now, even with advanced technology). Yet London continued to give Warsaw its own assurances by signing a formal mutual aid agreement between the United Kingdom and Poland on 25 August 1939, forcing Britain to declare war on Germany if it attacked Poland.  The Anglo-Polish Agreement was also signed on 6 April 1939. See Anita Prazmowska, United Kingdom, Poland and the Eastern Front, 1939 (Cambridge University Press, 1987), p. 193. The British and French governments had other plans than the execution of their contracts with Poland. On 4 May, a meeting was held in Paris, during which it was decided that “Poland`s fate depends on the final outcome of the war, which will depend on our ability to defeat Germany instead of helping Poland in the beginning”. [Citation required] The Polish government was not informed of this decision and Polish-British discussions continued in London.
Also in May 1939, Poland signed a secret protocol on the 1921 Franco-Polish military alliance, but it was not ratified by the French until 4 September. Seventeen years later, in the face of rising tensions with Germany, Poland and France felt it necessary to reaffirm the defence alliance they had formed after the First World War.  In mid-May 1939, the Polish Minister of War, General Tadeusz Kasprzycki, went to Paris for a series of interviews. For Kasprzycki, the aim was to clarify the conditions under which France would militarily support Poland. These talks culminated in the Franco-Polish Military Convention, which, according to historian Richard Watt, said that “if war broke out between Germany and Poland, the French would immediately take aerial action against Germany. It was also agreed that on the third day of the French mobilization, his army would launch a diversionary offensive on German territory, which would be followed by a major military offensive by the entire French army, which would take place no later than a fortnight after the mobilization.  The Franco-Polish alliance was the military alliance between Poland and France, active between the early 1920s and the outbreak of World War II. The first agreements were signed in February 1921 and officially entered into force in 1923. In the interwar period, the alliance with Poland was one of the cornerstones of French foreign policy. Towards the end of this period, it was, together with the Franco-British Alliance, the basis of the foundation of the Allies of the Second World War. Finally, in the last days of August, when war was on the horizon and Germany was massing more than a million men along the Polish border, London and Paris asked Warsaw not to provoke the Germans by fully mobilizing their forces.
By relying on their allies, the Poles did what they asked. When the German attack arrived, the Polish army was only partially mobilized, making the Wehrmacht much easier to divide the Polish defence and go deep behind the Polish lines.  In light of what we now know about the months leading up to the Second World War, one cannot help but accept the conclusion of the Polish scholar Anita Prazmowska: “After giving the guarantee of defending Poland, the British (one might add the French WFF) failed to develop an Eastern Front concept.