Estonia had pursued a policy of neutrality, but it was of no consequence after the Soviet Union and Nazi Germany signed the Molotov–Ribbentrop Pact on 23 August 1939. In the agreement, the two great powers agreed to divide up the countries situated between them (Poland, Lithuania, Latvia, Estonia, and Finland), with Estonia falling in the Soviet "sphere of influence". After the invasion of Poland, the Orzeł incident took place when Polish submarine ORP "Orzeł" looked for shelter in Tallinn but escaped after the Soviet Union attacked Poland on 17 September. Estonia's lack of will and/or inability to disarm and intern the crew caused the Soviet Union to accuse Estonia of "helping them escape" and claim that Estonia was not neutral. On 24 September 1939, the Soviet Union threatened Estonia with war unless provided with military bases in the country—an ultimatum with which the Estonian government complied.