Iran continued to advance its nuclear program in 2011, a CIA report indicated this week, adding, however, that Tehran's nuclear ambitions were frustrated by what the survey said were "some obstacles."

The findings were cited in an annual report on the "Acquisition of Technology Relating to Weapons of Mass Destruction and Advanced Conventional Munitions," submitted to Congress by U.S. Director of National Intelligence James Clapper.

In the last few days, top U.S. administration officials have expressed concern as a result of what they said was Iranian activities aimed against American forces and their allies in both Iraq and Afghanistan.

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U.S. Secretary of State Hillary Clinton described the risk of instability that the Iranian activity represents, warning, however, of the danger of taking military action to thwart it.

The CIA report released this week mainly reiterates assertions made by Clapper, as well as those made by the Pentagon's intelligence director Ronald Burgess and other senior officials as well as repeating data presented in reports by the International Atomic Energy Agency.

Mainly, the survey deals with Iran's actual capabilities, as opposed to estimates regarding what the Iranian leadership intends to do with those capabilities; the report equally excludes descriptions of Iran's behavior and the actions that could take place as a result of it.

According to Clapper, until the beginning of November 2011, Iran produced about 4,900 kilograms of low-grade enriched uranium in its Natanz facility, compared to 3,200 kilograms by November of 2010, and 1,800 kilograms the year before.

Following a further enrichment process, Iran accumulated, up until five months ago, 4,150 kilograms of uranium enriched to 3.5 percent and 80 kilograms of uranium enriched to 20 percent, which is still lower than weapons-grade enrichment levels.

In addition, while the number of centrifuges was reduced between August 2012 and November 2011 by about 10 percent – from 8,900 to 8,000 – the number of operational centrifuges in fact rose from 3,800 to 6,200.

Centrifuges, the report said, were installed in the underground facility in Fordo, near Qom, where Iran began enriching its uranium to 20 percent; the nuclear facility in Isfahan was shut down for maintenance from August 2009 to November 2011.

According to the report, Iran has almost exhausted its imported supply of "yellow cake," used in the enrichment process.

In the field of weapons development, the report claimed that Iran continued its work on long-range ballistic missiles, in addition to its development of missiles threatening naval vessels in the Persian Gulf; underground launch silos; satellite launching capabilities; and advanced communications systems.

Iran, in addition, is striving toward a completely independent ballistic missile assembly line, as it is still dependent on key foreign-made components, which it receives from firms, scientists, and engineers from North Korea, Russia, and China.

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U.S. intelligences also estimated that Iran had maintained its chemical and biological warfare capabilities, as well as developing what could be offensive applications of these capacities.

Regarding Syria's WMD aspirations, Clapper indicted that Damascus clandestine nuclear program, one on which it cooperated with North Korea, operated for more than a decade, since the late 1990s and until the 2007 destruction of the "Kibar" reactor.

According to the report, had the reactor not been destroyed – in an action attributed to the Israeli air force – the Syrian plant could have started producing weapons-grade plutonium. The IAEA's investigation of the "Syrian nuclear case" is ongoing.

In addition, Syria's ballistic missile stockpile continues to be extensive, with U.S. officials concerned of the possibility that the missiles could find their way outside Syria's borders.

Terror groups, al-Qaida specifically, are interested in nuclear, chemical, and biological capabilities, mostly in reference to relatively simple toxic materials. Counter measures reportedly disrupted al-Qaida's attempts to develop advanced offensive capabilities in these domains.