Despite warnings from close US allies, US President Donald Trump controversially recognised Jerusalem as Israel’s capital and started the process of moving Washington’s embassy from Tel Aviv to Jerusalem. Trump‘s decision came 50 years after Israel’s annexation of East Jerusalem, the West Bank, Gaza, Egypt’s Sinai Peninsula and Syria’s Golan Heights; 70 years after the UN resolution to partition Palestine; and 100 years after the Balfour Declaration.

Trump’s recognition of Jerusalem as the Israeli capital upended decades of US foreign policy and created scores of anti-US/anti-Israel protests worldwide, while effectively killing the idea that Washington is a neutral party in the Palestinian-Israel conflict among the few who still had that perception. Arab capitals have almost unanimously considered Trump’s decision on Jerusalem to be a sharp tilt towards Israel, and an indication of Washington’s support for the consolidation of the Israeli occupation of East Jerusalem. The Council of the League of Arab States, at the level of Arab foreign ministers, declared opposition to Trump’s decision and considered it not only invalid, but also a serious breach of international law.

Nonetheless, within Trump’s inner circle, there is a belief that the decision was opportune and made at an appropriate time. From these voices’ perspectives, Arab leaders must accept this decision and deal with the potential unrest which this move may create within their countries.

Perhaps one of the unintended consequences of Trump’s move is that his decision has now put the Palestinian issue back at the forefront in the Middle East. Indeed, since 2001, the wars in Afghanistan, Libya, Iraq, and Yemen, the Arab Spring revolutions, waves of sectarian violence, and the Islamic State of Iraq and the Levant’s (ISIL, also known as ISIS) meteoric rise to power have taken regional and global attention away from the struggle for justice in Palestine.

Undoubtedly, Trump’s recognition of Jerusalem as Israel’s capital will further isolate the US from the rest of the world. Given the administration’s rejection of Palestinian claims to East Jerusalem, in violation of international law which recognises East Jerusalem as belonging to the Occupied Palestinian Territories, Washington has signalled its abandonment of a two-state solution more than ever. To be sure, there is no other country that recognises the legitimacy of Israel’s annexation of East Jerusalem, which Trump has now endorsed. With strong support from the international community for a two-state solution to the Palestinian-Israeli conflict, the US is now alone with Israel’s government in opposing this plan. Although no objective observer previously saw Washington as being an honest peace broker between the Palestinians and Israelis, it is now abundantly clear that Washington is unable to play this role.

Odds are good that Tehran will capitalise on Saudi Arabia's relatively cautious condemnation of Trump's decision to add momentum to the Iranian regime's narrative that Washington's GCC allies, chiefly Saudi Arabia, are indifferent to Jerusalem and the Palestinian issue at large.

Although the Israeli government quickly embraced Trump and his approach to US foreign policy in the Middle East, the US president’s recognition of Jerusalem as the capital of Israel is costing Washington immensely throughout the greater Arab and Muslim world. It is doubtful that Saudi Arabia or other Gulf states allied with Washington will take actions against the US as a result of Trump’s decision; however, angry elements within their own societies may react against the US and its interests in the region in the form of terrorism and other violent actions. Unquestionably, the US president’s move on Jerusalem will create new risks for all of Washington’s allies in the Middle East, as the decision will offer extremist groups a valuable opportunity to capitalise on anti-US sentiment and direct such anger towards regimes that are close to the US and non-confrontational towards Israel.

How will Trump’s recognition of Jerusalem as Israel’s capital affect the Arab world’s geopolitical order?

It seems likely that the perception of Russia being a more responsible superpower than the US will only grow among Arabs. Russia’s strong condemnation of Trump’s decision will naturally sit well among Arab/Muslim governments and societies which are beginning to accept Moscow as an indispensable mediator in the region, and a pillar of a new security architecture, following Russia’s direct military intervention in Syria.

Iran, too, will likely stand to gain influence as a result of Trump’s decision. Whereas Tehran has suffered in recent years from a perception among Sunni Arabs that Iran’s foreign policy is naturally sectarian, Trump’s move offers the regime an opportunity to expand its soft-power influence among Arabs and Muslims of both sects, effectively weakening this perception of Iran being pro-Shia or anti-Sunni. Odds are good that Tehran will capitalise on Saudi Arabia’s relatively cautious condemnation of Trump’s decision to add momentum to the Iranian regime’s narrative that Washington’s GCC allies, chiefly Saudi Arabia, are indifferent to Jerusalem and the Palestinian issue at large.

Lastly, another way in which the US position on Jerusalem is likely to hinder Washington’s interests in the Middle East pertains to GCC-Israel relations. As the US has sought to promote more official relations between Tel Aviv and the six GCC members, the Arabian Peninsula sheikdoms – led by Bahrain – have recently signalled a growing interest in pursuing a partnership with Israel. Whether such a declaration of any official Saudi-Israeli alliance would have been possible without the establishment of a Palestinian state is unclear, yet it is unquestionably true that any hopes for such a development are far less realistic now that the Israeli occupation of Jerusalem and widespread outrage over Trump’s endorsement of it have started to receive much more attention in the Arab world.

The views expressed in this article are the authors’ own and do not necessarily reflect Al Jazeera’s editorial policy.