The Ranas' anachronistic regime wasn't able to survive long after World War II, from which over 200,000 soldiers returned with dangerous ideas of freedom and justice. In 1947 the British quit India, and with them went the Ranas' chief support. The new Indian government mistrusted the Ranas, and became genuinely worried about Nepal's weakness as a buffer state after the Communist takeover of China in 1949. Seeking stability, India signed a far-reaching " peace and friendship " treaty with Nepal in 1950 which, despite the upheavals that were to follow, remains the basis for all relations between the two countries.

Later the same year the strategic balance shifted again as a result of the Chinese invasion of Tibet, and the Nepali Congress Party , recently formed in Calcutta, called for an armed struggle against the Ranas. Within a month, King Tribhuwan had requested asylum at the Indian embassy and was smuggled away to Delhi; the next morning, the Nepali Congress Party launched simultaneous assaults on Birganj and Biratnagar. Sporadic fighting continued for two months until the Ranas, internationally discredited, reluctantly agreed to enter into negotiations. Brokered by India, the so-called Delhi Compromise arranged for Ranas and the Congress Party to share power under the king's rule, with Nepalis given the right to vote in the parliamentary-style democracy.

The compromise was short-lived. Tribhuwan , a previously retiring figure, emerged as a "hero of the revolution" and an adroit politician, and before the end of 1951 he had dismissed the Rana prime minister. This was an end to the Rana regime, but not Rana influence: by an agreement that has never been made public, the Shah royal family continues to appoint Ranas to most key military posts, and the families are inseparably tied by marriage (the queen is a Rana, and two of her sisters are married to two of the king's brothers). In his four years as king, however, Tribhuwan neither consolidated his power nor delivered the elections he promised. Unaccountable to the voters, the party bosses who controlled the interim government weren't much of an improvement over the Ranas.