German Chancellor Angela Merkel, left, meets with Turkish President Recep Tayyip Erdogan in Istanbul on Oct. 18. (Tolga Bozoglu/Pool/Reuters)

TURKEY FACES an extraordinary array of troubles, including war with the Islamic State and a proxy conflict with the Syrian regime of Bashar al-Assad; more than 2 million refugees, many of whom are embarking on dangerous journeys toward Europe; incursions in its airspace by Russian warplanes; renewed fighting with Kurdish insurgents in southeastern Turkey and Iraq; and the prospect that a Nov. 1 election will, for the second time in five months, fail to produce a decisive result.

The predictable inclination of many Western governments, especially those in Europe seeking to stem the flow of refugees, is to tackle this mess by striking deals with Turkish President Recep Tayyip Erdogan. The European Union is offering Turkey a package of $3 billion in aid plus political concessions in exchange for its help in cutting off the flow of refugees. In a visit to Turkey last weekend, German Chancellor Angela Merkel promised speedier negotiations on Turkey’s E.U. membership bid and a faster visa process for Turks traveling to Europe — pledges that can only help the ruling party in its attempt to regain the parliamentary majority it lost in the last vote.

The pandering to Turkey’s would-be strongman is a mistake. It is becoming increasingly clear that Mr. Erdogan has become a chief cause of the country’s instability, driving its polarization with his autocratic and increasingly reckless tactics.

The president has pursued an ugly campaign against the Kurdish Peoples’ Democratic Party (HDP) since it won representation in parliament in June’s vote. The breakthrough thwarted Mr. Erdogan’s hopes of winning a majority large enough to rewrite the constitution to enhance his powers — or, at least, enough seats for a one-party government that would allow him to act as a de facto strongman. In July, Mr. Erdogan launched a military campaign against the Kurdistan Workers’ Party (PKK), an insurgent group he claims is linked to the HDP; meanwhile, pro-government mobs attacked HDP offices around the country.

This conflict is a boon to the Islamic State, which is fighting Kurdish militia forces in Iraq and Syria, including a Syrian force that is supported by the United States but regarded as an enemy by Turkey. The Islamic State is probably responsible for two terrorist bombings of rallies organized by the HDP, including one in Ankara this month that killed at least 102 people. If the attacks were meant to deepen the divide between Mr. Erdogan and Kurds, they succeeded. Kurdish leaders blamed the government for failing to prevent both bombings, and the PKK responded to the first one, in July, by killing two Turkish police officers . That, in turn, gave Mr. Erdogan reason to launch his offensive.

Western leaders who now court Mr. Erdogan would have been wise to wait until after the election. Polls suggest his party could once again fail to achieve a majority, though the growing turmoil is reducing the chance of a free and fair election. The best result for Turkey would be the creation of a centrist coalition government — and the retreat of Mr. Erdogan from his autocratic ambitions. Unless Turkey can overcome its growing domestic polarization, it won’t be able to tackle its multiple crises — or be a reliable partner for the West.