In much of the region, authoritarian governments duel for power with political Islamists and militants as rival creeds and ethnic groups vie for dominance.
Yemen, Syria, Libya and Iraq are riven by wars. Israel and the Palestinians are still locked in their decades-old struggle, while Bahrain rumbles with unrest.
All 50 Muslim states whose leaders Trump will meet in the Saudi capital Riyadh are menaced by the rise of Islamic State, also known as ISIS or Daesh. He has promised to rid the world of the scourge of "radical Islamic terrorism".
Attitudes towards Trump are coloured by the actions of his first four months in power. Among them: his attempt to ban citizens of six mostly-Muslim countries from travelling to the United States; his decision to launch cruise missiles against a Syrian airbase to punish Damascus for a chemical weapons attack; and his decision to arm Kurdish militias fighting IS in Syria.
In short interviews, residents of the Middle East from all walks of life tell Reuters what they expect of Trump.
Marla Awad
Fine arts graduate Marla Awad, who works at an import and export company, poses for a photograph outside a pub in Old Damascus, Syria, May 15, 2017. "What matters to me was one very negative decision - his refusal to allow the Syrians to immigrate to America in a racist way, because travelling to it was a dream for me to fulfil my ambitions to study and work," Awad said.
Djamel Bouktech
Ali Bassem
Hidya Muhyiddin
Somar Hazim
Anonymous female fighter
Lara Shahin
Lara Shahin, 35, a Syrian refugee, poses at a workshop run under Jasmine, a project which hires and trains Syrian refugee women to create handicrafts, in Amman, Jordan, May 16, 2017. "Trump's decision to strike at the air base was a surprise move that raised my hopes the US President will take bolder decisions in future that would end President Bashar al-Assad's rule and allow me to return home to a democratic country," Shahin said.
Abdulaziz al-Anbari
Abdulaziz al-Anbari, 32, poses for a photograph at a shopping mall in Riyadh, Saudi Arabia, May 15, 2017."I think Trump as a Republican president will help improve relations with the Gulf states, especially Saudi Arabia. I do not want to commit on Trump's policy in Syria and arming the Kurds now. Let's wait and see what comes from his visit," al-Anbari said.
Sherine Haji
Sherine Haji, 23, a Kurdish female fighter from the People's Protection Units (YPG), rests in a hospital in Qamishli city, Syria, May 16, 2017. "The plan to arm the YPG is a decision taken late. We have experienced many heavy battles. If this support was happening in the first place, the advances would have been quicker. We would not have to sacrifice many lives," Haji said. "Now I'm wounded, I've lost two legs, but rather than aching because of my pain, I'm worried for my people. This must end, no one else should be in pain. There must be free and peaceful life in this country."
Ovad Chen
Ovad Chen poses for a photograph at his falafel shop in Jerusalem, May 16, 2017. "I see myself as a very simple person and I believe that at the end of the day, God controls everything. Therefore, it doesn't really matter what Trump is saying or doing in the Middle East or anywhere else," Chen said. "Even if we might think people are in any sort of control or power, this is all an illusion. God is the real king."
George Gharib
George Gharib poses for a photograph at his accessories shop in Beirut, Lebanon, May 15, 2017. "I do not expect any change in American policies towards the region, especially since President Trump is committed to moving the US embassy to Jerusalem and there is no intention to pressure Israel," Gharib said. "He will be like all previous presidents who came before him with bias and abiding by Israeli interests."