It’s said that the Gulf’s oil-rich Sunni princes are looking on nervously at the prospect of a Donald Trump presidency.

Among the many controversial remarks made at the height of Trump’s presidential election campaign was talk of a bar on Muslim entry to the United States and a possible closure of the country’s mosques.

Outraged by this, one Saudi royal, Prince Alwaleed Bin Talal, tweeted that such remarks were nothing short of “a disgrace”.

Donald Trump’s twitter response was characteristic of the man now set to be US president.

“Dopey Prince @Alwaleed_Talal wants to control our US politicians with daddy’s money. Can’t do it when I get elected.”

If Barack Obama never had the best of relations with the house of Saud, then few imagine it will be much different in the case of Donald Trump. But then who really knows what Donald Trump thinks when it comes to the Middle East?

Part of the problem in getting a clear picture of what a Trump presidency holds for the Middle East lies in the bewildering character of Trump himself.

To take one example, during his election campaign, he criticised his predecessors for becoming too entangled in the Middle East to only then last March suggest sending in a division of some 20,000-30,000 US troops to fight the jihadists of IS.

Perhaps the best way to gain any insight into the impact Trump might have on the Middle East is not to try and see it through his eyes but instead from the position of the key countries and leaders currently making the most impact on the region.

Let’s start with the Middle East’s warring despots and strongmen like Syria’s Bashar al-Assad and Egypt’s Abdel-Fattah al-Sisi. For them there is doubtless relief that Trump will most likely focus on America’s national interest rather than become overly embroiled in the region for ideological reasons or causes.

If the evidence so far is anything to go by, Trump will eschew any notions of intervention by way of regime change, nation building, human rights or democracy. Trump after all is man who has endorsed torture just as readily as the regimes of al-Assad and al-Sisi regimes have employed it.

Others too stand to gain should Trump adopt this standoff position. “Russia, Iran, Iraq’s Shiite militias, Syria and Hezbollah all benefit from America’s vacuum in the region and support Mr Trump,” says Jordanian analyst, Oraib Rantawi, founder and Director General of the Amman-based Al Quds Centre for Political Studies.

Perception in foreign policy is vital, particularly in the Middle East. Many other Middle East’s leaders too will be watching carefully for signs that a Trump administration is unwilling to prioritise the region and the stability it needs.

Should there be sufficient evidence of this or not being able to count on Washington, then regional players might feel compelled to shape their own interests with even more unilateral authority.

Over the last few weeks while in Iraq covering the battle to oust the jihadists of IS out of Iraq’s second largest city Mosul, I spoke with senior Kurdish officials who welcomed the prospect of a Trump presidency.

The very fact that he had at least expressed his support for the Kurds in their fight against IS and might continue to extend a degree of US military largesse in the direction of Kurdistan Regional Government (KRG) was good enough for them - for the time being at least.

But what if Trump in future chooses to turn the other way, will such regional players feel compelled to act unilaterally sensing their interests are under threat or perhaps look to other allies?

And speaking of interests under threat, those Saudi princes and royalty might have much more to worry about than Trump’s domestic election campaign threats of barring Muslim entry and closing mosques.

The Saudis and its allies in the Gulf Cooperation Council (GCC) will view any cosy relationship between a Trump administration and Vladimir Putin’s Russia that results in a hands-off policy toward Damascus as tantamount to acquiescence in Iranian dominance of Syria and Lebanon. Trump might not intend this of course, but it would be a side effect of shunting Syrian policy to Moscow, since Russia and Iran both want to keep al-Assad in power.

Turkey’s increasingly authoritarian president Recep Tayyip Erdogan will also likely feel left in the lurch by any Trump-Putin deal over Syria.

While Barack Obama’s personal relationship with the Saudis was never more than lukewarm but born out of what Washington saw as a strategic regional necessity, Trump looks set to get Saudi backs up even further. Much of the Gulf states collective anxiety stems from the fact that Trump of course has threatened to pull their US security umbrella unless they actually pay for it.

Not all Gulf royals are miffed though. Many have personal business dealings with the Trump empire, including stakes in such consortiums as Trump SoHo, his hotel condominium in New York. Few doubt also that human rights will get in the way of the continuing lucrative sale of arms to the Gulf, regardless of what Saudi Arabia is getting up to in Yemen

If there is one policy area however where the Saudis will certainly welcome Trump’s arrival in the White House, it’s over his take on the Iran nuclear agreement that was implemented in January.

The Sunni Islamic kingdom of Saudi Arabia would like nothing better than to see its great regional rival the Shia Islamic Republic of Iran undermined.

During his election campaign Trump lambasted the Iran accord and hinted he’d like to reimpose sanctions on Tehran.

For some time now inside the US there has been a vociferous and hawkish lobby that has been urging Trump to pull the rug on the deal.

“I think its basically the end game for the deal,” was how Richard Nephew, a Columbia University fellow who was the lead sanctions experts on the US negotiating team gloomily summed up where things might be heading.

Should a Trump presidency succeed in killing off the Iran deal then it will have profound implications both inside Iran which has a crucial election of it own looming and across the wider region.

Iranian president Hassan Rouhani a relative pragmatist who pushed for the deal hoping to open Iran’s reclusive society to the international economy said last week that Trump cannot change the agreement, but diplomatic analysts are not so convinced.

In a worse case scenario should it all fall apart we can look to Iranian hardliners gaining ground in the elections and calling the shots across the region where Tehran has tremendous influence from Syria to Lebanon and beyond. It could especially play havoc in Iraq, where just at the moment when IS appears militarily to be on the back foot, Iran might step up its meddling as payback to Trump for scuppering the deal.

In turn this will only further inflame Saudi-Iran tensions.

Which brings us to Washington’s long time ally in the region, Israel. Trump’s presidential campaign ran on the most hardline pro-Israel platform ever. For its part Israel’s right-wingers were overjoyed at his victory and wasted no time in clarifying what they saw his presidency meant for them.

“The era of a Palestinian state is over,” declared Israeli Education Minister Naftali Bennett in what can only be described as an incendiary remark. For so long now the perennial issue of Palestinian statehood has underpinned or helped fuel so much of the wider instability across the Middle East, so Bennett’s remarks do not bode well.

But even in the case of Israel where huge sections of the political establishment welcomed Trump’s win, there remains a distinct sense of caution and unease. Just as in Saudi Arabia this in part has to do with question marks over the continuation of military aid, but most significantly simply because of Trump’s unpredictability.

“Bibi is risk-averse and hates surprises,” one Likud politician was quoted as saying of Israel’s Prime Minister Benjamin Netanyahu last week.

“Trump is unexpected and volatile and Bibi is like many in the Republican establishment who see him as a wild card and don’t trust him.”

And in a nutshell there you have it, wild card, loose cannon, unpredictable, these are the Trump factors that appear to be preoccupying Middle Eastern leaders from Jerusalem to Tehran, Baghdad to Riyadh. The Middle East waits and watches anxiously, as does much of the world, to see what the next US president will bring their way.