President Recep Tayyip Erdogan’s re-election grants him five more years to deepen his conservative imprint on Turkish society and to realize his ambition of increasing the country’s economic and geopolitical power.

Turkey’s Supreme Election Council named Mr. Erdogan the victor after a runoff election on Sunday. He won 52.1 percent of the vote against the opposition candidate Kemal Kilicdaroglu, who had 47.9 percent with almost all votes counted, the council said.

The election was closely followed by Turkey’s NATO allies, including the United States, who have often seen Mr. Erdogan as a frustrating partner because of his anti-Western rhetoric and close ties with President Vladimir V. Putin of Russia, which have grown since Russia’s invasion of Ukraine.

Mr. Erdogan has given no indication that he plans to change his policies abroad, where he has sought to use Turkey’s place at the juncture of Europe, Asia and the Middle East to expand its influence, or at home, where has consolidated power in his hands and responded to an inflation crisis with unconventional measures that economists said exacerbated the problem.

Challenging him in the election was a newly united opposition that billed the election as a make-it-or-break-it moment for Turkish democracy. The opposition’s candidate, Mr. Kilicdaroglu, ran as the anti-Erdogan, vowing to restore civil freedoms and improve ties with the West. He billed himself as more in touch with common people’s struggles.

Here are some key takeaways:

Crises damaged but did not break Erdogan.

This was the most challenging election of Mr. Erdogan’s 20 years as Turkey’s most prominent politician, as prime minister since 2003 and as president since 2014. Before the initial vote, most polls suggested a tight race with Mr. Kilicdaroglu in the lead.

Analysts cited several reasons Mr. Erdogan might struggle. Anger at a painful cost-of-living crisis turned some voters against him. Powerful earthquakes in February killed more than 50,000 people and damaged hundreds of buildings in southern Turkey. Many quake survivors complained about the government’s slow initial response while the destruction raised questions about whether Mr. Erdogan’s haste to develop the country had encouraged unsafe construction.

Turkey’s historically fractious opposition set aside its differences to come together behind Mr. Kilicdaroglu and argued that change was needed to stop the country’s slide toward one-man rule.

Mr. Erdogan came to power 20 years ago amid anger at the government’s disastrous response to an earthquake near Istanbul in 1999 that killed more than 17,000 people. So many expected this year’s quake to hurt his standing as well.

But there few indications that it did.

Mr. Erdogan came out ahead in eight of the 11 provinces affected by February’s earthquake. His governing Justice and Development Party and its political allies fared even better, winning a majority of votes in the simultaneous parliamentary elections in all but one of the quake-stricken provinces.

Participation in the earthquake zone was also high, despite worries that many voters displaced by the destruction would struggle to return home to cast their ballots as is required. Although participation in the 11 quake-affected provinces was lower than the 88.9 percent of eligible voters who cast ballots nationally, in none of those provinces did turnout dip below 80 percent.

Interviews with quake survivors indicated many reasons that the disaster had not changed their political outlook. Some described the quake as an act of God that any government would have struggled to respond to. Others whose homes were destroyed said they had more faith in Mr. Erdogan to rebuild the affected areas than they had in his challenger.

Terrorism warnings resonated with voters.

Mr. Erdogan undermined the opposition by portraying its leaders as weak and incompetent, but one line of attack proved to be especially potent: accusations that they would be soft on terrorism.

The president repeatedly made this argument to voters, based on the opposition’s having received the support of Turkey’s main pro-Kurdish party. The government often accuses that party of collaboration with militants from Turkey’s Kurdish minority who have been at war with the Turkish state for decades, seeking autonomy.

Mr. Erdogan even went so far as to air videos at his rallies that had been doctored to show militant leaders singing along to Mr. Kilicdaroglu’s campaign song. Many voters believed him, saying in interviews that they did not trust the opposition to keep the country safe.

International observers reported no large-scale problems with the process of collecting and counting votes, deeming the process free.

But they noted the tremendous advantages Mr. Erdogan had before voting began, including his ability to unleash billions of dollars in state spending to try to offset the negative effects of inflation and other economic strains and the abundant, positive media coverage he received from the state-funded broadcaster.

Late on Sunday, Mr. Kilicdaroglu did not contest the vote count, but told his supporters that the overall election had been “one of the most unfair election processes in recent years.”

Many in the political opposition fear that the closeness of the race will lead Mr. Erdogan to crack down on his political opponents more aggressively to prevent such a stiff challenge in the future.

Economists warn that Mr. Erdogan resorted to expensive short-term tactics to insulate voters from inflation and prevent the value of the national currency from sinking further. But he can’t keep it up forever.

Turkey’s foreign currency reserves have declined steeply, meaning the country could lose its ability to pay back foreign creditors. And because much of that money has been spent to keep the currency stable, its value could dive once that spending stops.

Mr. Erdogan gave no indication during his campaign that he planned to modify his economic policies, despite stubbornly high, double-digit inflation that economists say has been exacerbated by his insistence on lowering interest rates instead of raising them to combat inflation, as orthodox economics recommends.

So regardless of what moves Mr. Erdogan would like to prioritize at the start of his new term, the risks of a currency crisis or recession are likely to demand his attention.

Gulsin Harman contributed reporting from Ankara, Turkey.