Relatively neglected from 1923 to 1939, the army underwent a rapid expansion during World War II and, after the war, was extensively modernized with the aid of U.S. advisers. Many officers feared that the DP threatened the principles of the secular progressive Kemalist state. Some younger officers saw the army as the direct instrument of unity and reform. On May 3, 1960, the commander of the land forces, General Cemal Gürsel, demanded political reforms and resigned when his demands were refused. On May 27 the army acted; an almost bloodless coup was carried out by officers and cadets from the Istanbul and Ankara war colleges. The leaders established a 38-member National Unity Committee with Gürsel as chairman. The Democrat leaders were imprisoned.

The ascendancy of the right, 1961–71

No party won a majority in October 1961. The CHP won 38 percent of the votes and 173 of the 450 assembly seats. The newly formed Justice Party (JP), led by the retired general Ragıp Gümüşpala, received 35 percent and 158 seats. The remaining seats were divided between two smaller parties—the Republican Peasants’ Nation Party, which took 54 seats, and the liberal New Turkey Party, which gained 65. The results demonstrated the enduring popularity of the old DP. Its votes had been divided among the three smaller parties, the majority going to the JP, which also emerged as the largest party in the Senate. The CHP had failed to hold all of its 1957 vote and had suffered by identification with the army coup.

The new Grand National Assembly elected General Gürsel as president. The CHP leader İnönü formed a coalition government with the JP, but the coalition survived only until June 1962, when it broke up over the question of an amnesty for the imprisoned Democrats. After some delay and splits within the parties, which led to the formation of the Nation Party by dissidents who withdrew from the Republican Peasants’ Nation Party, the CHP formed a coalition with the two smaller parties. This accelerated the tendency for former Democrat voters to turn to the JP.

In the local elections of 1963, the JP made extensive gains at the expense of the two smaller parties. This led to the breakup of the coalition, and, because the JP was unable to form a government, İnönü formed a minority government from his own party alone but with voting support from the New Turkey Party. The CHP government resigned after a defeat on the budget in February 1965 and was replaced by a coalition of all the other parties, under the leadership of an independent, Suat Hayri Ürgüplü; this coalition acted as caretaker until the elections of October 10, 1965.

In December 1964 a new electoral law introduced the principle of the “national remainder,” by which a certain number of seats were distributed to parties according to their proportion of the vote. The law was intended to operate in favour of the smaller parties and against the JP, but in the election of 1965 the JP won a surprising majority with 53 percent of the votes and 240 seats. The CHP received 29 percent and 134 seats and the smaller parties 76 seats. The new JP leader, Süleyman Demirel, a former engineer, was able to form a government.

Political moderation triumphed in the years 1961–65. The army stood aloof while power came gradually to a party that drew its main support from the same groups and areas as the Democrats and that espoused a similar philosophy. Attempts to restore army rule failed. Intervention proposed by senior officers in October 1961 was rejected by others. Two projected coups were foiled in February 1962 and May 1963. Members of a secret society within the army—the Young Kemalists—were arrested in April 1963. Criticism of the 1960 revolution was made illegal in 1962; army leaders contented themselves with occasional warnings against too rapid a rehabilitation of the Democrats. This peaceful political evolution can be ascribed partly to İnönü, who used his personal influence and prestige to restrain the army even while power ebbed from his own party. The price was the postponement of several reforms. The only significant progressive initiative of the early 1960s was the labour law of 1963, which legalized strikes and promoted an expansion of trade unions; by the 1990s about half of Turkey’s nonagricultural workers were members of a trade union.

The JP’s program embraced political and economic liberalization. The DP prisoners were released (1962–64), and their political rights were restored in 1969. The JP eschewed central economic planning and sought foreign investment in industry to provide growth. The policy had much success: over the period 1963–77 the gross domestic product grew strongly, and industry replaced agriculture as the major contributor to national income. But the JP failed to address new political problems caused by the rise of extremist parties of the right and left and by political violence.

Industrial development, urbanization, and the growth of trade unions provided a base for the development of a radical left that included a new trade union federation, the Confederation of Reformist Workers’ Unions (Devrimci Işçi Sendıkalari Konfederasyonu [DİSK]; founded 1967); a revolutionary youth movement, Dev Genç (1969); a socialist political party, the Workers’ Party of Turkey (WPT; 1961); and an armed guerrilla movement, the Turkish People’s Liberation Army (1970). These and similar groups espoused anticapitalist and anti-Western doctrines, and their followers, particularly in the universities, often supported them by violent action. The violence of the left was opposed by that of right-wing groups, of which the most prominent was the National Action Party (NAP), created in 1963 from the former Republican Peasants’ Nation Party and led by an ex-officer, Alparslan Türkeş. The NAP’s agenda combined Islam and Turkish nationalism and stressed education. As part of its organization, the NAP developed a paramilitary section, known as the Gray Wolves, that clashed with the leftists.

The JP’s failure to deal with increasing violence during the late 1960s was caused in part by its own internal divisions. A coalition of diverse groups, including prosperous farmers from western Anatolia and big and small businessmen, the JP fell victim to personal rivalries. Its victory in the 1969 election, with slightly less than half the vote, was narrower than its 1965 victory; moreover, it lost votes not to the CHP—which was supported by only about one-fourth of the electorate—but to smaller parties. However, a change in the electoral system had made it more difficult for these smaller parties to win seats, and the JP thus increased its parliamentary representation. In the new parliament the right wing of the JP, led by Sadettin Bilgiç, disappointed at its exclusion from the government, defeated Demirel in February 1970; the Demirel government continued but was much weakened by these events.