Few contemporary political rivalries have reached the level of mistrust between Saudi Arabia and Iran, especially after the 1979 Islamic Revolution, which prompted Ayatollah Rouhollah Khomeini to deride the Saudi monarchy and to work in earnest to topple it.

More recently, and after the eight-year Iran-Iraq war (1980-1988), the 1990 Iraqi invasion of Kuwait and its ensuing liberation, the 2001 American attack on Afghanistan and, especially, the 2003-2009 US War on Iraq, Tehran perceived Riyadh as an epochal foe whose custodianship of the holy cities of Makkah and Madinah were placed in doubt.

Of course, both countries defined themselves as Islamic, although intrinsic differences on the very definition of the Islamic state, coupled with important socio-economic preferences, meant that Iran and Saudi Arabia pursued conflicting foreign policies. As a G20 member, the kingdom rose into the position of a leading regional power with global responsibilities, whereas Iran sought to lead what it called revolutionary movements in Iraq, Syria, Lebanon, Palestine, Egypt and, especially, throughout the Arabian Peninsula.

W. Andrew Terrill, a Middle East specialist at the Strategic Studies Institute of the US Army War College, identifies various changes in the two countries and offers 15 specific recommendations to his readers in the American policy community.

Although the retired US Army Reserve Lieutenant Colonel and Foreign Area Officer identifies significant changes throughout the Gulf area and the wider Middle East, his assertion that “the Saudi leadership is uncomfortable with the idea of expanding regional democracy” (page 2), was unsubstantiated. Saudi Arabia was a monarchy and, naturally, looked with grave concern at the possibility of radical governments threatening Arab monarchies. That explained the ruling family’s willingness to respond favourably to a call from Bahrain for assistance in 2011 after Manama determined that Iran was behind some of the actors organising the uprising on the island kingdom.

Moreover, because Saudi Arabia enjoyed strong ties with leading Western powers, especially the United States and the United Kingdom, Iran viewed those relationships in the most negative terms possible, concluding that Washington represented the kernel of evil in the region. Irrespective of this erroneous connotation, it was worth noting that the most conservative Sunni Muslim Arab state forged exceptionally close ties with Washington as early as 1945, even if a relatively liberal Shiite Iran was long considered to be an American ally, at least under the late Shah.

Much changed in the interim and in 2013, it was safe to affirm that leading Iranian politicians considered their country to be the defender of minority Shiite populations throughout the world, and were at a loss when majority Sunnis rejected blatant interferences in internal Arab affairs. As a result, Riyadh and Tehran viewed the politics of a number of regional states as perfect arenas where they could freely displayed putative “influences”.

In the aftermath of the waves of pro-democracy and anti-regime protests in 2011, Terrill concludes, the Saudi-Iranian rivalries will intensify and, in turn, affect the interests of the US. Although the author believes that in some instances, Saudi opposition to Iran could serve US interests, he affirms that inherent dangers loom over the horizon. Towards that end, he cautions Washington to be wary of Riyadh, allegedly because the latter remains a deeply anti-revolutionary state.

His 15 recommendations include several worth quoting, if for no other reason than to elucidate what Washington policymakers must digest:

2. U.S. intelligence officials and policymakers must also be aware of the possibility that Saudi Arabia may overestimate Iranian involvement in any regional crisis and may conflate Shiite assertiveness with Iranian activism on the basis of very little evidence.

5. The U.S. civilian and military leadership must be aware of the fact that Saudi influence is not always an effective counterweight to Iranian activism in many instances, including those where US-Saudi Arabia interests overlap.

6. The United States must remain aware that local powers such as Saudi Arabia are sometimes viewed as overbearing by even their closest allies.

15. The United States should remain aware of political changes that might occur in Iran in the hope that meaningful dialogue on security issues may become possible at some point (pages 55-62).

If Tehran successfully portrayed itself as the leading regional power supporting the Shiites everywhere, its decision to don the Palestinian mantle proved to be the single most crucial straw that broke the camel’s back. That effort, coupled with its massive involvement in Syria, enhanced Iran’s regional influence, though it also crystallised Riyadh’s responses. Hamas jettisoned Iran, returning into the Arab fold and one wondered how Iran prepared for the inevitable transformations under way in Syria and Lebanon. Beyond the rivalries, one hopes Washington factors in its decision-making process inevitable changes, including Arab calls for stability instead of perpetual chaos.

Dr Joseph A. Kechichian is an author, most recently of “Legal and Political Reforms in Saudi Arabia” (London: Routledge, 2013).