The centre-right minority coalition between the Motherland Party of Mr Yilmaz and Tansu Ciller's True Path Party was cobbled together in March under pressure from those who fear the Welfare Party most, a secular republican establishment that includes big business, media barons and the powerful military. But even after signing a coalition protocol for a rotating premiership, the two youthful leaders competing for the future captaincy of Turkey's sinking centre-right could not overcome a personal rivalry that borders on hatred.
The slow-witted Mr Yilmaz was stubbornly convinced he could force Mrs Ciller's party to dump her by deploying allegations of corruption, including a parliamentary investigation into her great wealth. But he reckoned without Mrs Ciller's legendary toughness and charisma. She first ordered ministers to boycott their own coalition government, and when that warning move failed, simply joined the Welfare Party in agreeing to a vote of no-confidence that was to be held on Saturday.
Finding himself out-flanked, Mr Yilmaz found a pretext, a court annulment of the government's original vote of confidence which he had previously dismissed, to hand his resignation yesterday to President Suleyman Demirel.
The Yilmaz administration will now remain in office in a caretaker capacity until a new government is set up, a process that could take up to 45 days. If the government is not formed by July 21, the President must call new elections.
Turkish markets reacted mildly to the situation. Private business has largely shrugged off political turmoil that dates back to September, even though there are some signs of economic slowdown and a hesitation by foreigners to invest. Uncertainty arises over whether there will be a Welfare Party element in the next government, and what it might do. The confusion, which Mr Yilmaz said showed that Turkey was moving towards an "Italian-type democracy", as if that was something desirable, has also helped the wily and quietly ruthless President Demirel become a central player in Ankara.
But eyes are mostly on the Welfare Party leader, Necmettin Erbakan, 70, who should be asked to try to form a government first. Welfare controls the largest bloc of seats in parliament, having come first with 22 per cent of the vote in the December 1995 elections. Itconsolidated this lead in local by-elections on Sunday, climbing by three percentage points to reach 33.6 per cent in the 41 municipalities in question. Mr Yilmaz's share dropped by five percentage points to 21 per cent and Mrs Ciller's by four to 12 per cent.
Mr Erbakan is calling for a grand right-wing alliance with both Mr Yilmaz and Mrs Ciller. To look more presentable, he seems determined to rein in his anti-Semitism, his dream of an Islamic common market led by Turkey and his deeply held beliefs about a Western plot against Islamic nations. In an interview with Milliyet newspaper yesterday, Mr Erbakan pledged that the Welfare Party was committed to democracy, not to changing the way people dressed, ate or drank.
He promised not to take Turkey out of Nato, that he would stick with the customs union with Europe and that he would consult with the Turkish military about the future of the allied air force that protects the Kurds of northern Iraq from President Saddam Hussein.
The Turkish establishment may try to put together another secular coalition, but the parliamentary arithmetic looks difficult. The military, despite some speculation, is unlikely to intervene directly to prevent the Welfare coming to power. That idea is only popular with the most fundamentalist secularists of the old republican school and diplomats from one or two continental European countries.
Ordinary Turks know that Welfare Party is not single-mindedly radical on the Iranian or Arab model, even if Mr Erbakan has a dictatorial nature. It also represents only one of several Islamic currents of thought and organisation in Turkey. Its administration of the two main cities since 1994 has been relatively honest, unusually effective and, although encouraging Islamic traditions, seemingly free of signs of forcing people to become Islamic.
Leading article, page 11