US officials warn Iran is close to building nukes

>>> rising tension not only in egypt, but across the middle east . and the u.s. appears to be caught in the middle of the turmoil. nbc's chief foreign correspondent, richard engel is with us in new york with details on that. richard, good to see you.

>> obviously this is a campaign year and a lot of attention is being focused on domestic politics. but there is a very important looming crisis in the middle east that has a lot of u.s. political figures, u.s. military figures deeply concerned. and it's centered in iran . iran , according to u.s. officials and israeli analysts, could have a testable nuclear weapon in a year and a half. israel , iran 's sworn enemy, might not wait that long to act, with an attack. israeli leaders are increasingly vocal in warning that iran with a nuclear weapon is a threat to its existence.

>> a nuclear-armed iran is a threat to israel , to the region, to the world.

>> u.s. military officials and analysts are increasingly worried about a military conflict with iran , perhaps before this summer. a strike, they say, could set back iran's nuclear program . maybe years. but not necessarily stop it. and oil, according to u.s. military estimates, could shoot to $200 a barrel. iran would likely respond to israeli aggression, with a missile retaliation on israel , u.s. interests in the middle east , or according to u.s. intelligence officials, with possible attacks inside the united states .

>> the growing concerns that israel has, and that the countries in the region have and indeed all of us have, about the continued activities by iran , along a path that could, if the decision is made to pursue the construction of a nuclear device .

>> tensions with iran are decades old. but dramatically increased over new year's. the united states imposed tough new sanctions. the sanctions punished nations for trading with iran . iran 's customers are already canceling orders for oil. china is demanding reduced prices. for iran , it may be unsustainable. something has to give. and iran is only one of the challenges in the middle east . and they're all intertwined. in syria, iran 's ally, the government is fighting for survival. its security forces have killed thousands of demonstrators. u.s. military officials say syria is also unsustainable. and this year will turn. it's unclear how. in egypt, the muslim brotherhood , the world's oldest islamic group , is dominating the new parliament. so much for jeffersonian democracy , sprouting from the old arab spring. washington is trying not to isolate the new brother rood.

>> i think if we see democratic change in the arab world , probably the new democratic governments are going to be more critical of foreign policy in the region.

>> an attack on iran is by no means a foregone conclusion. even some israeli officials are divided on the subject. and i've been told that the u.s. military is trying to encourage israel not to do it they want to see if the sanctions can work and there's still some belief that the sabotage efforts that have been taking place inside iran are having an impact.

>> especially against their nuclear scientists.

>> their nuclear scientists, weapons facilities and i thimplg we'll see more of them. and there's also this possibility that if the sanctions don't work, the israelis may lose patience with this and decide to act on their own.

>> richard, thanks very much for your report.