Iran is expected to achieve a "critical capability" to produce sufficient weapon-grade uranium by mid-2014, without being detected, the Institute for Science and International Security (ISIS) said in a report on Tuesday.
According to the Washington-based think tank, Iran would achieve this capability by implementing its existing plans to install thousands more IR-1 centrifuges at its declared Natanz and Fordow centrifuge sites.
To counteract this development, the ISIS recommended that the International Atomic Energy Agency (IAEA) should increase inspections of Iranian centrifuge facilities to at least twice per week.
"However," this ISIS warned in their July report, "there is an inherent limitation and dilemma to increasing the rate of inspections, despite their importance."
If the United States and Israel hesitate to strike out of fear of facing international opposition, the ISIS warned, "Iran could have time to make enough weapon-grade uranium for one or more nuclear weapons."
According to the report, breakout times at critical capability would be "so short" that there would not be enough time to organize an international diplomatic or military response.
IAEA inaction or caution could make an international response all but impossible before Iran has produced enough weapon-grade uranium for one or more nuclear weapons," the ISIS report stated.
In its recommendations, the ISIS suggested increasing the frequency of inspections and pushing for remote monitoring of the nuclear sites as conditions for progress in negotiations.
"The point is that by themselves these measures are not sufficient if Iran reaches critical capability," the report cautioned.
According to the ISIS, there are reasons to conclude the Iran could now be building a new centrifuge plant, "based primarily on Iranian officials’ past statements."
A new plant could produce sufficient weapon-grade uranium relatively quickly if the centrifuges worked well, the ISIS reported.
"The immediate priority must be limiting the number and type of Iran’s centrifuges at Natanz, Fordow, or a site not yet finished," the ISIS stated, calling on the P5+1 negotiators to achieve the suggested conditions and prevent the progression of the Iranian nuclear program.