Its forces have performed badly; although well-equipped and disciplined, Saudi Arabia has discovered - as have many other countries in the past - that defeating Iranian-supplied proxy militias is hard.
Nonetheless, the Saudi determination to fight Iranian influence remains undiminished, whether it is in Yemen, Bahrain or Syria.
The coming year, therefore, belongs to more proxy fighting by even more regional actors.
But the Saudis are also getting better at orchestrating diplomatic efforts to isolate Iran. Saudi-Russian relations are improving rapidly, with the Saudis offering to support higher oil prices (something Russia badly needs) in return for Moscow declining to supply Iran with sophisticated weapons.
The Saudis fear Mr Donald Trump's disdain for all Arab regimes, as expressed during the United States' electoral campaign.
But they hope that the prospect of fat profits for US companies will persuade the new administration to re-engage in the region.
Israeli Prime Minister Benjamin Netanyahu should rejoice at Mr Trump becoming the leader of his country's most important ally and partner. Mr Trump has pledged to move the US embassy from Tel Aviv to Jerusalem, breaking with more than half a century of traditional American policy. He has also pledged unstinting support for Israel's refusal to negotiate with Palestinian leaders.
Mr Trump has already appointed his ambassador to Israel, an American of Jewish faith who is an enthusiastic supporter of Israeli settlements on occupied Palestinian lands, something which all previous US administrations deemed illegal.
Still, Mr Netanyahu's relationship with Mr Trump will not be trouble-free. The Israeli premier is still in the dark over what footprint the US wishes to maintain in the region.
Enthusiastic support for Israel without any bigger commitment to regional security will not be in Israel's long-term interest.
Although Mr Netanyahu is happy to see the back of President Barack Obama, he must be worried about the polarisation of US domestic politics, which places America's Jewish community - the world's biggest - in the difficult position of having to choose between Democrats, their traditional electoral home, and the newly ascendant Republicans.
Ultimately, however, what will trouble Mr Netanyahu most is that Mr Trump might outflank him in Israel's own domestic policies.
Having cultivated the image of a hawk, Mr Netanyahu now risks appearing as a dove, in comparison with some of the policies which Mr Trump himself is advocating.
Syrian President Bashar al-Assad has won his gamble. After five years of civil war during which he refused any compromise and any offer of exile, he now looks more secure in power than ever.
But that will not restore the unity of his country. Mr Assad might remain in control of Damascus, the capital, as well as a handful of other cities, yet he is even more beholden to his Russian and Iranian allies than ever before, and even less likely to reinstate the remit of his government to the entire country.
At the very best, Syria will remain a country divided into rump states, some run by Sunni rebels, others under the control of Kurds, while pockets of territory remain under the direct control of Russian, Turkish or Iranian troops.
That is not what the anti-Assad fighters had in mind when they launched their revolution in 2011.
But that is the most Syria can hope for now.
At the very best, the country will come to resemble neighbouring Lebanon, perpetually divided into mini, quasi-states, all with external paymasters.
Despite calling Iran the "single most enduring threat to stability and peace in the Middle East" and despite some of the key ministers being perceived to be anti-Iranian, the new US administration is unlikely to tear up the Iran nuclear deal.
The document is a broad multilateral agreement involving not only the US, but also Britain, China, France, Russia, Germany and the European Union.
Hence, any unilateral American decision to withdraw from it will raise hackles with allies, thereby complicating America's global diplomacy.
Still, there are major questions over Iran's compliance with the deal, which the new US administration is guaranteed to raise. And incoming US Defence Secretary James Mattis has already expressed deep concerns about Iran's behaviour in the region, indicating that he would be interested in rolling back Teheran's influence.
Nor should it be forgotten that General Mattis apparently lost his previous job as a US military commander under President Obama due to what was perceived at the time to be his "extreme" attitudes towards Iran.
The expectation remains that Mr Trump will try to avoid a direct confrontation with Iran, at least not in the first year of his presidency.
But there is no question that the Islamic Republic is bracing itself for renewed confrontation with Washington.