"The regime [Bahrain] is desperate. It sees that whatever has happened in the last 12 months has not safeguarded its position. The revolution is still on, the invasion by Saudi troops has not really crushed the movement…"
- Saeed Al Shehabi, Bahrain opposition activist
Bahrain has summoned Iran's charge d'affaires to protest against what it calls a "gross violation of its sovereignty", after Tehran criticised efforts by Gulf Arab states to forge a closer political and military union.
The proposed union calls for economic, political and military integration.
The latest Gulf Co-operation Council (GCC) meeting ended with no decision, but this did not stop Iran from hardening its tone, calling on Iranians to protest on Friday against what it described as a US plot to annex Bahrain.
Analysts say a closer union between Gulf states is part of a much broader defence strategy to counter Iran's influence.
Last year's 'Arab Spring' protests found their way to Bahrain in early February, with the Shia majority complaining of discrimination by the Sunni royal family and the security forces.
"This is two independent states deciding their fate, Iran has no business in it. It's now been revealed that Iran is trying to revive its claim to Bahrain, which started in 1956 .... This is the major issue here, the Iranian objection coming from that dimension."
- Mustafa Alani, a military analyst
It did not take long for Saudi Arabia to react. In March, it led 1,500 Gulf troops into Bahrain to "help secure government installations".
It was the first time the soldiers from the GCC nations had intervened in another member state.
Iran described this as an "unacceptable" presence of foreign troops in Bahrain, while the Bahraini royal family accused Iran of supporting the mass protests.
Bahrain then recalled its ambassador to Tehran in protest at what it called "blatant interference" in its internal affairs.
Fast forward just over a year, and Iran is now calling for demonstrations against the Saudi-Bahrain unity proposal.
Ali Larijani, the speaker of Iran's parliament, reportedly said: "If Bahrain is supposed to be integrated into another country, it must be Iran and not Saudi Arabia."
"Iran cannot do anything as far as the unity proposal is concerned … but the issue is the Bahraini people, the UAE people, the Saudi people, the whole question of democratic movement in the region."
- Sadegh Zibakalam, an Iranian foreign policy expert
Inside Story asks: Now that Saudi Arabia is again talking up the idea of a full union of Gulf states, is it once more trying to show Iran that it will not be messed with? And what is the latest escalation in tensions between the two regional heavyweights likely to achieve?
Joining presenter David Foster to answer these questions are guests: Abdel Aziz Abu Hamad Aluwaisheg, the assistant secretary-general for Negotiations and Strategic Dialogue at the Gulf Cooperation Council; Sadegh Zibakalam, a political science professor at Tehran University, a political analyst and an expert on Iranian foreign policy; Mustafa Alani, the director of the National Security and Terrorism Studies Department at the Gulf Research Center; and Saeed al-Shehabi, a Bahraini opposition activist and member of the Bahrain Freedom Movement.
"[The unity proposal] is a native-driven process, the main objective stated as far back as 1981 is to consolidate, integrate the six countries with the goal of unity at some point in the future .... This call has been going around long before the 'Arab Spring'."
Abdel Aziz Abu Hamad Aluwaisheg, the assistant secretary-general for Negotiations and Strategic Dialogue, GCC
WHAT IS THE GCC?
- The Gulf Co-operation Council is a loose political and economic alliance made up of six Gulf Arab states
- Formed in May 1981 against the backdrop of the Islamic revolution in Iran and its war with Iraq
- Members include Saudi Arabia, Kuwait, the United Arab Emirates, Oman, Qatar and Bahrain. All share similar political systems and a common social and cultural outlook. They are absolute monarchies with limited or non-existent political participation
- In 1984, the GCC created an embryonic collective defence force - the Saudi-based Peninsula Shield of 10,000 soldiers. But the GCC has failed to expand it. Oman's proposal in 1991 to set up a 100,000-strong joint military body was turned down
- The Peninsula Shield made no attempt to deter or counter the Iraqi invasion of Kuwait that year, but was controversially deployed to Bahrain in March 2011 to bolster security during anti-government protests.