Dueling summits and the emergence of a bipolar Middle East

You have these three countries convening in Sochi:

The trilateral meeting between Iran, Russia and Turkey in the Russian resort of Sochi this week was "a right step, at the right time" for stability in Syria, Iranian President Hassan Rouhani told Syrian counterpart Bashar al-Assad.

Russia's Vladimir Putin won the backing of Turkey and Iran on Wednesday to host a Syrian peace congress, taking the central role in a major diplomatic push to finally end a civil war all but won by Assad.

“Sochi summit … was a right step at the right time," Rouhani was quoted as saying by state news agency IRNA on Saturday in a phone call with Tehran’s main regional ally.

He said a national congress to hold face-to-face talks between government and opposition could be "a step towards stability and security of Syria."

Iran has signed large economic contracts with Syria, reaping what appear to be lucrative rewards for helping Assad in his fight against rebel groups and Islamic State militants.

"Tehran is ready to have an active role in reconstruction of Syria," Rouhani added.

The chief commander of Iran’s Revolutionary Guards, who has sent weapons and thousands of soldiers to Syria to prop up Assad's regime, also said on Thursday that their forces were ready to help rebuild Syria and bring about a lasting “ceasefire” there.

And these 41 countries meeting in Riyadh:

Saudi Arabia's crown prince vowed to "pursue terrorists until they are wiped from the face of the earth" as officials from 40 Muslim countries gathered Sunday in the first meeting of an Islamic counter-terrorism alliance.

"In past years, terrorism has been functioning in all of our countries... with no coordination" among national authorities, Prince Mohammed bin Salman, who is also Saudi defence minister, said in his keynote address to the gathering in Riyadh.

"This ends today, with this alliance."

The summit is the first meeting of defence ministers and other senior officials from the Islamic Military Counter Terrorism Coalition, which officially counts 41 countries and identifies as a "pan-Islamic unified front" against violent extremism.

The alliance was announced in 2015 under the auspices of Prince Mohammed, whose rapid ascent since his appointment as heir to the throne in June has shaken the political scene across the region.

Sunday's meeting comes as several military coalitions, including key Saudi ally the United States, battle to push the Islamic State group from its last remaining bastions in Iraq and Syria.

The alliance groups largely, although not exclusively, Sunni-majority or Sunni-ruled countries.

It excludes Saudi Arabia's arch-rival, Shiite-dominated Iran, as well as Syria and Iraq, whose leaders have close ties to Tehran.

A player to watch in all this is Turkey. Has Erdogan decided that his bread is buttered on a particular side?

And then there's the phone conversation the other day between Trump and Erdogan, in which Trump says he would quit arming the Kurdish fighters in Syria.  How does this fit with what Mackubin Owens sees as an emerging Trump Doctrine, one built on healthy nationalism, a state-centric view of international politics, armed diplomacy, prioritizing of economic growth and leveraging the new geopolitics of energy, and a defense of (classical) liberal principles? Is it of a piece with such a doctrine, or would that be expecting too much consistency from a guy known for winging it?

And then there's the nationalist fervor within Iran that is uniting pro-regime zealots and reformists.

Is this doctrine, if it really is shaping up to be a thing, adequate for addressing that?