The fierce diplomatic controversy that erupted Monday over UN Secretary-General Ban-ki Moon's announcement that he had invited - and subsequently disinvited - Iran to attend this week's Geneva II talks on exploring ways to end the Syrian conflict, highlights the contradictory regional and international complexities that define this situation: Foreign interventions in Syria have helped bring this war to its terrible current situation, and yet only robust international engagement can offer any hope of winding it down.
The easy answer to the question of whether Iran should attend the Geneva meetings is a straightforward and emphatic "yes", because Iran's assistance to the Syrian government headed by President Bashar al-Assad is crucial for keeping the Damascus government in place. Yet nothing is easy when it comes to finding a diplomatic solution to the war in Syria, because the matter of Iranian involvement raises more vexing issues related to regional and international confrontations that bind the United States, Russia, Saudi Arabia, Iran, Israel, Hezbollah and others in an intense ideological struggle to define the character and condition of the region.
A sub-plot of the debate about whether Iran should be invited to Geneva without preconditions, or only after it accepts the conditions laid down by the US and its allies, revives long-standing Iranian determination to be treated with respect and not to have its sovereign rights mangled by foreign powers.
The Iranian government logically must participate in the Geneva talks because its role in Syria is central to developments in that war; and what happens in Syria is deeply linked to, and will influence, future developments across much of the Middle East, which in turn will shape the influence of the US, Russia and Saudi Arabia across the region. Iran's central role in Syria mirrors, and is part of, its wider positioning and influence across the Middle East, so it is deeply invested in the current and future condition of the Assad government.
Iran has shown beyond doubt that it is prepared to go to great lengths and expend much money, arms, troops, and political support to maintain Assad's incumbency, even if only over half a country that will emerge from the war deeply wounded and polarised. Iran’s relations with Syria and Hezbollah in Lebanon are the most tangible and lasting regional successes of the Islamic revolution that overthrew the Shah in 1979. A strong political relationship with Damascus is critical for Iran's continued tight alliance with Hezbollah.
These three actors form the "Deterrence and Resistance Front" that seeks to check or roll back the influence of the US and Israel in the region, while also assisting local actors in other countries that join it in confronting the policies of Saudi Arabia across the region. The overthrow of the Assad government would be a major blow to Iran’s regional network of allies and would seriously weaken its stature and influence across the Middle East. It would probably also embolden Saudi Arabia and others, who fear Tehran's links with Shia Arab populations, to step up their political confrontations with Iran in countries like Lebanon, Iraq, Yemen and Bahrain.
It seems naïve to think that a political agreement can be reached to establish a post-Assad transitional process in Syria without Iran's active involvement or assent, which is not likely to happen now. Iran's continued robust support to fortify the Assad government - directly and via its close ally Hezbollah - indicates that it is not willing today to sacrifice Assad's rule as part of a peace agreement in Syria.
It seems naïve to think that a political agreement can be reached to establish a post-Assad transitional process in Syria without Iran's active involvement or assent, which is not likely to happen now.
Iranian policy, like Syria's and Hezbollah's, is based on the principle of active resistance and sacrifice in the face of what it sees as American-Israeli-Saudi desires to smash the Syrian-Iranian-Hezbollah alliance and re-order the region according to the interests of the US and its allies.
So Tehran seems willing to continue supporting Assad at almost any cost, which is why a Geneva process that excludes it is bound to fail. Like Russia, Iran says that the future of the governance system in Syria must be decided by the Syrian people, not by American or Arab convictions that the Assad government has lost its legitimacy and must be brought down. Should American and other support for anti-Assad rebels succeed in further weakening and toppling the government in Damascus, Iran would join Russia and others in fearing that this would open the path to Washington unilaterally deciding the fate of other Arab or Iranian governments or non-governmental groups such as Hezbollah and Hamas.
It is not clear what positions Iran would take at the Geneva talks, but it is fair to assume that its acceptance of any transitional governing arrangements in Syria would expect that Assad and his co-rulers in the country would be part of that process, and not its first discarded political relics. This is based on the assumption in Tehran that Assad will not be overthrown by force. The wider question that remains actively discussed around the region is how Iran would react should Assad start to lose ground militarily to strengthened opposition forces, and reach a point in the year ahead where his demise appeared imminent. Would Iran cut its losses, drop Assad as a lost cause and focus instead on maintaining Hezbollah's strength and influence in Lebanon? Would Iran eventually sacrifice Assad gracefully for the bigger prize of the US and Saudi Arabia accepting it as an equal strategic player and even a partner in the Gulf region, especially in the wake of a successful Iranian nuclear power/sanctions lifting process?
We will have to wait for answers to these hypothetical questions, but there is no doubt that Iran's substantial influence in Syria, Lebanon and Iraq is vital for any successful outcomes in Geneva - and, more importantly, that its influence across much of the region could sabotage any moves on Syria that it does not explicitly approve and help define.
Rami G. Khouri is director of the Issam Fares Institute for Public Policy and International Affairs at the American University of Beirut, and an internationally syndicated columnist. He tweets at @ramikhouri
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.