Bahrain this week accused the Lebanese Hezbollah group of responsibility for a series of bombings in the Bahraini capital Manama.The five bomb blasts, in the Adliya and Gudaybiya districts of the city, came amid renewed protests by members of the island’s 70 percent Shi’a majority against the Sunni Khalifa monarchy. Two Asian cleaning workers were killed.Information Minister Samira Ibrahim bin Rajab issued the accusation against Hezbollah. She said that the terrorists were operating according to principles set by Iranian Supreme Leader Ali Khamenei, and further accused the Iranian media of inciting against the monarchy. The minister did not offer any concrete evidence to back up her accusation of Hezbollah’s involvement.Official Bahraini claims of Iranian interference in the internal affairs of the island are nothing new.The ruling al-Khalifa family has long sought to locate the protests against it in the context of the cold war between anti-Western Iran and the Sunni Gulf monarchies, which are pragmatically aligned with the West.As an ally of the West, and the host of the US Fifth Fleet, the Bahraini monarchy is keen to depict its internal struggles as a local manifestation of a broader conflict.Critics of the monarchy argue that this is a comfortable narrative for the rulers of Bahrain to promote.It enables them to downplay or ignore very real claims of discrimination and exclusion levelled by the Shi’a majority.This tendency manifests itself in concrete ways. In September, for example, a Bahraini civilian court upheld very harsh sentences against leaders of last year’s uprising. A prosecution official said that “some of the accused had relations, and strived to have relations and intelligence contacts, with a foreign organization, Hezbollah, which works in the interests of Iran.”But while the instrumental value for the monarchy’s accusing Iran is obvious, this does not of itself render the accusations groundless. No concrete evidence has yet been offered to back up claims of Hezbollah or the Revolutionary Guard’s military support for the Bahraini opposition. Indeed, the Bahraini revolt against the monarchy has been largely non-violent in nature.But there is considerable evidence to suggest that Tehran is offering financial and political assistance to the opposition in Bahrain. The regime of the mullahs has long claimed ownership of the island, which it refers to as Iran’s “14th province.”The assertion of this claim has not been confined to mere declarations.Tehran directly assisted a failed pro- Iranian coup attempt by the so-called Islamic Front for the Liberation of Bahrain in 1981.A recent report produced by the American Enterprise Institute traced the financial support of a number of Iranian clerical offices, including that of Khamenei, for the Bahraini opposition.An investigation by a London newspaper into the “Bahrain Freedom Movement,” based in the British capital, found that the movement’s leader, Dr. Saeed Shehabi, worked out of offices directly owned by the government of the Islamic Republic of Iran.Hassan Mshaima, who was among the opposition leaders jailed for life in May, went as far as proposing Iranian military intervention in support of the uprising last year.Mshaima, leader of the powerful Shi’a Islamist Haq movement, made these remarks in an interview with the pro-Hezbollah Lebanese Al- Akhbar newspaper.Senior Iranian officials, up to and including Khamenei, have been vociferous in their overt support for the Bahraini uprising. The Iranian state media has also kept up a steady drum-beat of condemnation of the Bahraini authorities. The criticism grew angrier following the Saudi and GCC military intervention in support of the Bahraini monarchy in March 2011.From a Western point of view, there is an obvious cynicism at the heart of Iranian support for the Bahraini protesters. Iran crushed similar protests at home in 2009.Tehran is deeply involved in the brutal Assad dictatorship’s struggle for survival in Syria.But, of course, the Iranian cynicism is directly mirrored by the Saudi approach, which supports revolt in Syria and suppression of protests in Bahrain.Support for representative government and the right to protest are not factors. The motivation is sectarian and concerned with power.Where the Sunnis are in power – in Bahrain, for example – the Saudis back the Sunnis. Where the Sunnis are in rebellion, as in Syria, Riyadh is with the rebels. The Iranians use the same logic – supporting the rebels in Bahrain and the ruling authorities in Lebanon, Syria and Iraq.A Sunni-Shi’a arc of conflict, centered on the rival interests of Tehran and Riyadh, is now bisecting the Middle East. This arc stretches from Lebanon, via Syria and Iraq, taking in Bahrain, Kuwait and the eastern province of Saudi Arabia and extending to north Yemen.In each of these areas, Sunni and Shi’a Arabs are competing for power.In each area, the Iranians back the Shi’a interest while the Saudis and, to a lesser extent the smaller Gulf monarchies, back the Sunnis.For both sides sectarian identity is the defining factor.Saudi and Gulf concerns arise from their accurate identification of Iran’s regional ambitions and its methods for building power and influence.The Iranians lack powerful conventional armed forces. The tools they utilize are those of creation and/or sponsorship of proxies, political subversion, sectarian propaganda and, where relevant, the use of paramilitary methods.The Saudis, with a less successful track record in political warfare, are trying to counter the Iranian push using similar methods.No matter who was directly responsible for the explosions in Bahrain this week, it can be said with certainty that the bombings and their aftermath were another episode in this ongoing, region-wide contest.This contest is notable for the absence of an external guiding hand on either side. Both sides estimate that the US has chosen to unilaterally withdraw from regional leadership.The Iranians are happy about this. The Saudis are dismayed.Neither side is democratic. Sectarian loyalties mark the borderline.The roots of the enmity go down into past centuries.The Sunni-Shi’a arc of conflict looks set to form the key strategic process in the period now taking shape in the Middle East.