A coalition administration could oversee a retuned foreign policy that would return Turkey to its default position as a Western-allied, mainly Muslim country that can transcend the religious, sectarian and ethnic divisions elsewhere in the Middle East. This would entail a less assertive and more cautious policy toward Syria, where Ankara has been prone to dangerous meddling. A more pro-European stance would also bring more pressure to bear on Turkey’s European Union allies to clear the way to an eventual Turkish accession.

In coming days, the A.K. Party’s chairman and prime minister, Ahmet Davutoglu, will meet with Kemal Kilicdaroglu, the C.H.P. leader, to discuss the conditions of each for forming a coalition administration. At present, both the leaderships and grassroots of both parties are divided on the issue.

Forming a minority government is not an option for the A.K.P., since there’s no obvious incentive for any element of the opposition, excluded from executive power, to back the A.K. Party. The only other choice it does have would be to form an alliance with the Nationalist Movement Party, or M.H.P. But the nationalists’ leadership has made the suspension of talks on a Kurdish settlement a condition of its participation in a coalition.

For the A.K.P., such an alliance would further erode its support among Kurds and liberals. So an alliance with the C.H.P. appears to be the A.K.P.’s safest option.

The C.H.P., which will have difficulties reaching an accommodation with its ideological rival, could also try to form a minority government with the M.H.P. and the predominantly Kurdish, left-of-center People’s Democratic Party, or H.D.P., which won 80 seats by surpassing, for the the first time, the parliamentary threshold of 10 percent of the popular vote. But irreconcilable differences between the two parties will probably preclude an alliance.

The opportunity for the C.H.P., which has not governed since 1979, to return to power — even though it means partnership with the A.K.P. — may therefore prove irresistible. But to win the backing of his base, Mr. Kilicdaroglu will still need to gain his coalition partner’s agreement to a reform agenda that would include lowering that 10 percent threshold in national elections and overhauling the law on political parties, as well as consolidating the rule of law and improving freedom of expression and association.

The C.H.P. leader would also need to obtain guarantees that forming a coalition with A.K. Party will not prevent the Turkish Parliament from investigating corruption allegations against four members of the previous A.K.P. government.