U.S President Barack Obama won8217;t trip over Netanyahu8217;s Iran 8216;red line8217;

Officials and analysts say Iran has warded off the Israeli threat by calibrating its mid-level uranium enrichment so that it does not accrue enough fuel for a potential first bomb 8211; the threshold Netanyahu warned about in a United Nations speech in September. 

He was presenting a worst-case extrapolation from U.N. nuclear inspector reports. The most recent of those,however,found a slowdown in the stockpiling of the 20 percent fissile uranium that Iran,in the face of mounting Western suspicions,says is part of an entirely peaceful programme. 

Netanyahu has not publicly revised the spring-to-summer 2013 dating for his 8220;red line8221;. But several Israeli officials privately acknowledged it had been deferred,maybe indefinitely. 

8220;The red line was never a deadline,8221; one told Reuters. 

The chief U.S. military officer,General Martin Dempsey,has questioned Israel8217;s ability to deliver lasting damage to Iran8217;s distant,defended facilities. Netanyahu,meanwhile,has made little secret of preferring that Washington take the lead in any war. 

Yet while mobilising Gulf forces and saying it was open to military force as a last resort,the Obama administration has resisted Israeli calls to present Tehran with a clear ultimatum. 

CLOCKS AND KILOS  Interviewed by Israel8217;s top-rated television news programme on Thursday,Obama voiced cautious hope that negotiations,re-launched last month between the United States,five other world powers and Iran,could still curb its disputed nuclear drive. 

8220;There8217;s a window 8211; not an infinite period of time 8211; but a window of time where we can resolve this diplomatically,and that it is in all of our interests,8221; he told Channel Two TV. 

The U.S. 8220;red line8221; was Iran reaching the verge of acquiring a nuclear bomb,Obama said,adding: 8220;That would take over a year or so 8230; But obviously we don8217;t want to cut it too close.8221; 

Confidence in Obama is not unanimous among Netanyahu8217;s circle. While one Israeli official,speaking to Reuters on condition of anonymity,said 8220;American presidents don8217;t bluff8221; and that therefore Obama should be trusted,another worried U.S. planners might miss an Iranian dash to nuclear arms capability. 

A Feb. 21 U.N. report said Iran had 167 kg 367 pounds of mid-level enriched uranium,in gas form,after converting some of the stockpile to solid reactor fuel. Experts say it would need 240 kg to 250 kg of the gaseous material for a bomb,though the fuel would have to be further enriched to 90 percent purity. 

Yet Iran has also been expanding centrifuges at an underground site so that it could rapidly ramp up mid-level enrichment if it wanted to,diplomats say. 

Netanyahu alluded to those developments on March 4 when he reiterated his 8220;red line8221; in a speech to a pro-Israel lobby in Washington,saying Iran was 8220;putting itself in a position to cross that line very quickly once it decides to do so8221;. 

The second Israeli official posited Iran could gather 230 kg to 240 kg of mid-level uranium 8211; just short of a bomb8217;s worth 8211; and then,between inspectors8217; weekly visits to the enrichment plants,churn out the few kilograms required to close the gap. 

Next,it could move all the material to a secret location for prospective later processing into weapons fuel,making the Islamic Republic a 8220;latent nuclear power8221;,the official argued. 

8220;For now,we know what sites would have to be targeted in a military strike,8221; the official said. 8220;Can any of us,even the Americans,be sure of having such full knowledge in the future?8221; 

The United States sounds more secure about nuclear inspections and intelligence monitoring of the Iranians,as well as in its ability to intervene militarily at short notice. 

8220;We assess Iran could not divert safeguarded material and produce a weapon-worth of WGU weapons-grade uranium before this activity is discovered,8221; U.S. National Intelligence Director James Clapper said on Tuesday. 

STRATEGIC AMBIGUITY  Gary Samore,Obama8217;s former nuclear non-proliferation adviser,disputed the idea that Iran would break out of the U.N. inspections regime with just one bomb8217;s worth of fuel,or that it would be capable of making a quick switch to the highest level of uranium enrichment,given its technical lags. 

8220;Nobody knows,including the Iranians,how much 20 percent enriched uranium they need to have a bomb8217;s worth. They have never done it. They have never converted,8221; Samore,who is now executive director at Harvard Kennedy School8217;s Belfer Center for Science and International Affairs,said in a phone interview. 

That made threshold questions 8220;inherently ambiguous8221;,said Samore,who referred to Netanyahu8217;s 8220;red line8221; alternatively as a 8220;red zone8221;. 

Mark Fitzpatrick,a former U.S. State Department official who heads the non-proliferation and disarmament programme of London8217;s International Institute for Strategic Studies,had similar doubts about whether Iran would try to sneak past Netanyahu8217;s 8220;red line8221; and,if so,whether Israel would respond with strikes. 

8220;Nobody8217;s going to make a war-or-peace decision based on a few kilograms of 20 percent enriched uranium,8221; he said. 8220;Nobody knows what Israel8217;s real 8216;red line8217; is. I don8217;t think Israel knows either.8221; 

Fitzpatrick faulted Netanyahu for locking on to Iran8217;s 20 percent enrichment,arguing that this risked distracting from ongoing progress in other risky aspects of its nuclear programme like centrifuge improvements and stores of low-purity uranium. 

8220;That may not have been a clever way of putting it,because Iran is able to make tactical adjustments and can push back the so-called 8216;red line8217; as long as it wants,8221; he said. 

But Fitzpatrick also saw a tactical gain for Netanyahu 8220;in reminding the world that there was a concrete threat here,after the world has heard so much sabre-rattling from Israel8221;. 

Israel,which is reputed to have the region8217;s sole atomic arsenal,has spoken about being ready to attack Iran for close to a decade 8211; rhetoric some Israeli officials say was designed,at least in part,to stiffen the determination of war-wary world powers to find a diplomatic alternative through sanctions. 

Samore said the international coalition had been 8220;deeply energised for years8221; in confronting Tehran. 8220;I think we still have a reasonable prospect of stopping them,and that if the Iranians misstep,the U.S. will act,8221; he said.