President Erdogan failed to clinch the first round in a nailbiter election on Sunday, catapulting Turkey into two weeks of uncertainty as the country heads toward a runoff vote. The incumbent won 49.35 percent of the vote while in second place was the single opposition candidate Kemal Kılıçdaroğlu, taking 45 percent of the vote with all ballots counted according to the state-run news agency Anadolu.

To win in the first round, candidates needed to get 50 percent of the votes plus one vote, which clearly did not happen. 

Mr. Erdogan, now 69 and chronically ailing, greeted his failure to secure an outright majority to extend his two-decade rule of the NATO-member country coolly, telling supporters at Ankara early Monday: “We don’t yet know if the elections ended in the first round … if our nation has chosen for a second round, that is also welcome.”

This year’s election largely centers on domestic issues such as the economy, civil rights, and a February earthquake that killed more than 50,000 people. Western nations and foreign investors also awaited the outcome because of Mr. Erdogan’s unorthodox leadership of the economy and often mercurial but successful efforts to put Turkey at the center of international negotiations.

The mild-mannered Mr. Kılıçdaroğlu is seen as promising a more Western-oriented, secular, and democratic path for the country of 85 million people, which is one of the world’s largest economies. “We will absolutely win the second round … and bring democracy,” Mr. Kılıçdaroğlu 74, the candidate of a six-party alliance, told his supporters, arguing that the nation’s trust in Mr. Erdogan has eroded.

Voters in the large cosmopolitan cities of Turkey’s Aegean coast, such as Istanbul and Izmir, tended to favor Mr. Kılıçdaroğlu at the ballot box, while as predicted Mr. Erdogan found more favor in the vast and generally more rural inland provinces of Anatolia. 

According to Turkey’s election authority, the Supreme Electoral Board, the majority of ballots from the 3.4 million eligible overseas voters still needed to be tallied, and a May 28 runoff election was not assured. It looks likely, though, as does a brief period of extreme economic volatility as the country grapples with soaring inflation. 

The managing director of the Strategic Advisory Services consultancy, Hakan Akbas, told the Greek newspaper Kathimerini that the next two weeks “will probably be the longest two weeks in Turkey’s history and a lot will happen. I would expect a significant crash in the Istanbul stock exchange and lots of fluctuations in the currency.”

While the country is deeply polarized, Mr. Erdogan has an advantage moving forward because his ruling alliance, the Islamist-rooted AKP, looked set to have a lock on a majority in parliament. 

The election has been keenly followed not just in Greece, which shares a border with Turkey and has often borne the brunt of Mr. Erdogan’s blunt approach to international issues best served by a less indelicate hand, but in the rest of Europe and Washington, too. 

Mr. Erdogan has undeniably helped modernize Turkey, but an economic policy of low interest rates triggered soaring inflation and has eroded some voter support he may once have taken for granted. 

His neo-Ottoman pretensions, harsh treatment of journalists perceived as critical of his government, and often bellicose stance with Greece on certain territorial issues regarded by the rest of the world as settled long ago have won him few plaudits on the European stage. Worse, his cozying up to President Putin has raised the hackles of the Biden administration as well as other countries in Europe and the Middle East. 

The Associated Press reported that while Mr. Erdogan hopes to win a five-year term that would take him well into his third decade as Turkey’s leader, Mr. Kılıçdaroğlu campaigned on promises to reverse crackdowns on free speech and other forms of democratic backsliding, as well as to repair an economy battered by inflation that has lurched as high as 86 percent, though is currently lower, and currency devaluation.

Voter turnout on Sunday was high, with nearly 90 percent of  64 million eligible voters reportedly heading to the polls. 

Despite Mr. Erdogan’s many detractors globally and domestically, he still has a robust loyal base which is at best ambivalent about the secular legacy of the first president of Turkey, Mustafa Kemal Atatürk. Because 2023 marks 100 years since Turkey was established as a republic, the final election results this month will have both practical relevance and historical resonance.