On 27 March 1941, two days after the agreement had been signed, the Yugoslav government was overthrown when the regency led by Prince Paul was ended and King Peter II fully assumed power.

[1] Thus, the historian Vladislav Sotirović wrote that "no wonder British politicians and diplomats tried by all means, including military coups, to drag any neutral country into war on their side for a final victory against Hitler's Germany".

[6] In an extremely uncomfortable discussion for Paul, Hitler said that after he would expel British troops from Greece, he would invade the Soviet Union in the summer to destroy bolshevism.

That was hinted to be Paul himself, whose regency mandate would end on 6 September 1941, when Peter II would become an adult and thus the legitimate king of Yugoslavia.

[5] However, the offer, which was more imaginary than realistic, was not crucial in influencing Paul's decision to accede to the Tripartite Pact on 25 March 1941[7] since it was Realpolitik that was the ultimate factor.

Paul had first addressed British diplomatic circles in Belgrade and London to urge help and protection, but Britain offered no military aid to Yugoslavia, despite doing so for Greece.

[7] During the negotiations with Hitler, Paul feared that London would demand a formal public declaration of friendship with Britain that would only anger Germany but bring no good.

[8] On 6 March, Yugoslav War Minister Petar Pešić, despite being supported by the British since he was anti-German, laid out the slim chances of Yugoslavia against Germany.

[9] Accordingly, the next day, Dragiša Cvetković sent his demands to the German embassy in Belgrade: the respect of the political sovereignty and the territorial integrity of Yugoslavia, the rejection of military aid from or the transport of troops across Yugoslavia during the war and the taking into consideration of the country's interest for an access on the Aegean Sea during the postwar political reorganisation of Europe.

[6] Hitler had modified his demands by making special concessions to Yugoslavia that would include nothing "contrary to her military traditions and her national honour".

It was generally concluded from the discussions that accession would occur[6] but that certain limitations and reserves were to be demanded from Germany, with Cincar-Marković in charge of drafting those points, which would be held in highest secrecy.

[12]The next day, Cincar-Marković called Viktor von Heeren, the German minister in Belgrade, to the ministry and informed him of the Crown Council had agreed to Hitler's wish for Yugoslav accession to the pact.

[12] Simultaneously, an uneasiness, sparked by anti-Yugoslav manifestations and the negative articles in the media in Bulgaria in recent days, came to the fore.

[12] Then, Ribbentrop was asked to clarify through Heeren whether Yugoslavia would receive a written statement from Germany and Italy if it acceded[12] that Yugoslavia's sovereignty and territorial integrity would be respected; that no Yugoslav military aid would be requested and, during the creation of a new order in Europe, that the Yugoslav interest in free access to the Aegean Sea through Thessaloniki would be considered.

He stated that he had a strong impression that Yugoslavia had already decided that it would soon join the pact if the Germans either fulfilled the demands presented by Cincar-Marković or only slightly amended the German-Italian written statements.

[12] In Belgrade's political and military circles, joining the German camp was generally discussed, but the thought that it would come in stages, with the help of government statements, prevailed and that by not acceding the pact would spare the population's hostile mood.

[14] After consultations with British and American ministers, the Crown Council decided that the military situation was hopeless and voted 15–3 in favour of accession.[when?

The new Yugoslav government, under Prime Minister and General Dušan Simović, refused to ratify Yugoslavia's signing of the Tripartite Pact and started negotiations with the United Kingdom and the Soviet Union.