making money. >> what this look, or even this one has to do with socially conscious business. >> ifill: in moscow, margaret warner talks with with alexei navalny, a leading reformer, four days before the russian presidential elections. >> woodruff: and we close with an update on the news corp story, as james murdoch steps down as head of the scandal ridden newspaper arm of the company. >> ifill: that's all ahead on tonight's "newshour." major funding for the pbs newshour has been provided by: >> and by the bill and melinda gates foundation. dedicated to the idea that all people deserve the chance to live a healthy productive life. and with the ongoing support of these institutions and foundations. and... this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. >> woodruff: from washington and pyongyang came word today of a new deal to freeze north korea's nuclear program. it would come in exchange for food assistance from the u.s. secretary of state hillary clinton confirmed the agreement at a congressional hearing this morning. >> today's announcement represents a modest first step in the right direction. we, of course, will be watching closely and judging north korea's new leaders by their actions. >> woodruff: under the deal, north korea agreed to put in place a moratorium on long-range missile launches and to suspend work to enrich uranium at its yongbyon nuclear facility. the north also promised to allow the return of u.n. nuclear inspectors to verify its claims, for the first time since 2009. for its part, the united states will provide some 240,000 metric tons of food aid. the agreement followed talks in china last week, between u.s. and north korean negotiators. it was the first such meeting since north korea's longtime ruler kim jong il died in december and was succeeded by his son, kim jong un. secretary clinton today called it a reminder that the world is transforming. >> the united states-- i will be quick to add-- still has profound concerns. but on the occasion of kim jong il's death, i said that it is our hope that the new leadership will choose to guide their nation onto the path of peace by living up to its obligations. >> woodruff: this is not the in 1994, former president jimmy carter-- acting for the clinton administration-- brokered a deal for pyongyang to shut down nuclear plants in exchange f u.s. aid in building electrical power plants. the yongbyon plant remained closed until 2002 when both sides accused the other of not living up to the agreement. from there, the north went on to test-fire long-range missiles and conduct its first underground nuclear test. in 2007, the bush administration, along with south korea, russia, china and japan negotiated a new halt to north korea's nuclear program. this time, north korea again agreed to disable the complex at yongbyon, and it received one million tons of fuel. the disabling was halted months later though, after the u.s. and north koreans were unable to agree on verification measures. given that history, white house spokesman jay carney was asked today about prospects for this new arrangement. >> the agreements that the north koreans have made are very welcome, but obviously they need to be followed up by actions. and commitments to do something are one thing; actually doing them are another. so we will pursue this policy area with that... with that approach in mind. >> woodruff: for now, word that north korea will step back from nuclear weapons work, was welcomed today in japan and south korea. for more on all of this we get two views. former u.s. ambassador to south korea donald gregg. he's now chairman emeritus of the board of the korea society. and balbina hwang, a visiting professor at georgetown university who was a korea specialist at the state department during the last bush administration. and we thank you both for being here. ambassador gregg, to you first, how big a breakthrough is this? >> i think this is very significant. it a test first major step forward taken by the two countries since president obama came into office. and it also, i think, says a lot about the way the kim jong-un regime in north korea is going to operate. they're a very hierarchical country, and it's interesting to me that kim gay wan who has been promoted is happy to meet with gwen davis, a lower rank than the man he succeeded, steve bosworth. so there was no talk of hierarchy, there was just talk on issues that had long divided us and which we were able to talk about since kim jong-un came into power. >> woodruff: balbina hwang, do you agree this is a big break through? >> i don't, unfortunately. i would hesitate to call it a step in the right direction. the problem is the bar has been moved so far backwards that even if we return to where talks stalled in october, 2008, i'm not sure this statement today gets us to that point. it's certainly leaning in the right direction and i think it's a positive sign but i hesitate to read too much into this. >> woodruff: what about ambassador tkpwr +*el gregg's pt you have ranking officials on the north korean side that are willing to meet with less ranking folks from the u.s. side. >> i'm not sure that's quite the calculation. glen davies was the ambassador for i.a.e.a. of the united states in vienna so he does certainly is ambassadorial status. i think the more important point here is to make sure we don't read too much into this being a tremendous sign of kim jong-un's new regime and that this is a tremendous sign of change. because, in fact, the statement reveals it was actually very carefully crafted and i think it actually shows a great deal of continuity with the old regime. >> woodruff: ambassador gregg, what do you see, though, in here, that gives you hope? you mentioned the different levels, the officials who came, the sense that this new regime in north korea wants to talk. what else do you see in here that gives you hope? >> well, part of it is the new attitude shown by ambassador davies. he welcomed the signs of continuity which the things that he heard from kim gae hwan. and also the agreements that the north koreans have set in place are going to test how quickly they are willing to implement these new steps. it's up to them to reach out to the i.a.e.a. to arrange procedures for inspections at i don't think bee i don't think. they've been told no food will be delivered until there are monitors set up in inside north korea. now the koreans when they want to do something can do it quite quickly. i saw that when i accompanied the new york philharmonic on their visit to north korea three or four years ago. the north koreans moved very adroitly and gave a wonderful reception. so we will quickly know whether they're serious about these agreements by the speed with which they will reach out to the i.a.e.a. and arrange to have food monitors put in place. >> woodruff: why isn't that, balbina hwang, a promising sign that something could happen in a positive direction and quickly? >> certainly it is a positive sign. on the other hand, i think there's a very long way to go before this leads to any real progress in terms of the overall goal of deknew clearization and certainly even kick-starting the actual six party talks. >> woodruff: that's a reference to the... the multinational process that has been in place for pretty much the last decade. the problem is even if the i.a.e.a. inspectors come in, it's unclear from the north korean statement-- which is quite different from the u.s. state issued today-- on whether or not that even brings us back to where the six party talks stalled in october, 2008. it does not specifically state plutonium which is the problem with the actual nuclear weapons they have today. >> woodruff: in fact, ambassador gregg, as we understand it, the north korean statement didn't mention uranium, it didn't mention plutonium. what's the significance of that? >> well, that's very significant because the nuclear weapons they have produced have been produced througthrough plutonium, not ur. so it's clear from what ambassador davies has said is that our goal is to get at denuclearization of north korea. but these steps are in the right direction and i would stougt balbina and others who are so deeply skeptical that we stop looking backward to where we have been but let's look forward to where we can go and what has been agreed to in beijing sets a very clear path toward preliminary steps that can lay the basis for significant negotiations on denuclearization in the future. but that's going to take time. it isn't going to happen immediately because there are decades of mistrust between our two countries that we have to overcome. but this is a really major step in the right direction in my view. >> woodruff: what about that as an approach, looking ahead rather than back? >> certainly we should do that. but also history has much to teach us and i think the point here is in this statement one very important missing piece was no mention about interkorean relations. now, i know the u.s. state department... >> woodruff: with south korea? >> that is correct, improving relations between north korea and south korea. now the state department has said that that was included in the dialogue with... in beijing with the north koreans and that the u.s. position has not changed on that. however, i'm not certain how much of a priority that is and that concerns me a great deal. >> woodruff: ambassador gregg, what do you look for next to give you a sense of whether this agreement may bear fruit eventually? >> well, i think it's important for the united states to maintain very good relations with south korea and it's interesting to me that the south koreans have approved this agreement. i also look for reactions from within north korea to what has been agreed to because we've all been saying can kim jong-un really make it as a new leader? he's less than 30 years old. but the information of this agreement... the implementation of this agreement will validate his leadership in north korea if it brings food to mothers and small children that will be taken as evidence in north korea that he is a successful leader who's establishing better relations with the outside world than north korea has had for some time. so i think there are positives to this agreement both in pyongyang and the united states and south korea as well. >> woodruff: just briefly, would you agree those are the next steps to look for? >> they are, but i would caution about the food aid. if, in fact, we are prefacing our shipments of food aid based on monitoring, if north korea cannot meet those requirements then from the message that kim jong-un sends to his people is that the united states reneged on the deal. so, again, it is... we have to be quite careful with all of these steps and measures. >> woodruff: well, we thank you both. breaking and entering know what hwang, donald gregg. >> ifill: still to come on the "newshour": the republican delegate puzzle; business with a conscience; an opposition voice from russia and upheaval at rupert murdoch's news corp. but first, with the other news of the day. here's hari sreenivasan. >> sreenivasan: at least nine people were killed in the midwest early today as an outbreak of tornadoes ripped across the region. more than 30 others were hurt, and a series of small towns suffered heavy damage. the view from the air over harrisburg, illinois was one of near-total devastation. entire roofs were stripped off homes, walls caved in on others and other buildings were unrecognizable just piles of shredded lumber. >> it's a horrific event that's happened to us here in harrisburg. the loss of lives, the injuries, the devastation is just. it's very profound and it's heartbreaking to tell you the truth. >> sreenivasan: crews were already at work clearing debris while stunned residents searched through what was left of their homes. the community of 9,000 had taken a direct hit from a storm, with peak winds of 170 miles an hour. >> it's unbelievable. i can't believe the measure of damage it did to this building. it's like there was no structure and it just took it completely out. i mean as you can tell it's total devastation. >> sreenivasan: the deadly string of storms trekked steadily eastward as the day wore on, beginning in small towns in kansas, and moving through missouri, illinois and kentucky. in all, the national weather service reported at least 16 tornado sightings. one of them hit the well-known music theater town of branson, missouri. >> there's eight to nine mile track of damage. bounced along here and did significant damage. >> sreenivasan: in neighboring kansas, nearly 40% of the town of harveyville was damaged. >> all of a sudden the windows >> sreenivasan: the storms were spawned when a broad cold front coming off the rocky mountains slammed into warm, humid air over the eastern half of the u.s. in syria, government troops and tanks pushed into a rebel-held area in the battered city of homs. it appeared to herald a ground offensive to recapture the neighborhood of baba amr. that section of the city has been under heavy bombardment for more than three weeks. the u.n. now estimates that more than 7,500 people have died in syria since the uprising began, one year ago. egypt has lifted a ban on allowing seven americans-- employed by pro-democracy groups-- to leave the country. the seven were charged with using illegal foreign funding to incite unrest against egypt's military leaders. in response, the u.s. threatened to cut off nearly $1.6 billion in aid. nine other americans were also charged. they've already left egypt. the u.s. economy is doing better than the federal reserve expected. fed chairman ben bernanke told a house hearing today that the drop in unemployment has exceeded projections. at the same time, he said the fed expects that trend to slow, as the year progresses. >> notwithstanding the better recent data, the job market remains far from normal: the unemployment rate remains elevated, long-term unemployment is still near record levels, and the number of persons working part time for economic reasons is very high. >> sreenivasan: bernanke left open the possibility of upgrading the fed's economic outlook. wall street saw it as a signal that the central bank will take no further action to boost growth and that sent stock prices falling. the dow jones industrial average lost 53 points to slide back under 13,000. it finished at 12,952. the nasdaq fell nearly 20 points to close below 2,967. there was more today on disclosures that remains of some victims from the 9/11 pentagon attack ended up in a landfill. a 2002 memo showed the disposal was based on written guidance from david chu. he was pentagon personnel chief at the time, under defense secretary rumsfeld. all indications are that unidentified remains were incinerated, then taken to a landfill. pentagon officials say the practice ended in 2008. for the first time, a high-value detainee at guantanamo has reached a plea deal. a pakistani man-- majid khan-- admitted today that he helped plot al-qaeda attacks. u.s. military prosecutors said he had talked of trying to blow up fuel tanks in the u.s., and of assassinating pervez musharraf, the former president of pakistan. khan has been held for nearly a decade. he has agreed to testify against other detainees, in exchange for a reduced sentence. singer davy jones, who starred with "the monkees" in the 1960s, died today, of a heart attack, in indiantown, florida. jones and three others were recruited in 1966 for a t.v. show about the adventures of a pop band. it lasted two years. the monkees had a string of hits, including "last train to clarksville" and "daydream believer." davy jones was 66 years old. those are some of the day's major stories. now, back to gwen. >> ifill: we turn now to the presidential campaign as the candidates turned their attention to next week's big super tuesday contests. mitt romney beat rick santorum by just three points in michigan last night. but that didn't stop him from his victory lap. >> we didn't win by a lot, but we won by enough, and that's all that counts. ( cheers ) >> ifill: even that narrow win over a stiff santorum challenge proved enough to head off what would have been an embarrassing loss for romney in his home state. a clearcut win in arizona awarded romney 29 delegates, and michigan officials said the close finish there would give each candidate 15 delegates each. with ten states voting on super tuesday next week, romney moved on to the next big potential prize today-- ohio. >> the reason i won yesterday in michigan and in arizona was because i'm talking about the issue people care most about-- and i understand that issue personally. and that's the economy and job creation, balancing budgets. the skill of creating more jobs, with less debt and smaller government is something i understand. when the media asked people coming out of polls yesterday why they voted for me, what their interests were, those people that cared most about the economy and jobs voted for me. >> ifill: santorum took his campaign to another super tuesday state, tennessee. his strong michigan showing, he said, put wind at his back. >> we went out there with a positive, hopeful message. a message about jobs, a message about energy, a message about faith and family and the importance of that as foundational institutions of our country and you know what, the people of michigan across the board, across the board, responded to that. and we're out of here today, >> ifill: newt gingrich and ron paul did not contest michigan or arizona. for gingrich, the path to revival runs through the south. he spent today in georgia, the state he represented in congress. >> we need to stand up and we need to win this. and i think the way we win it is we draw very broad distinctions. so if you help me next tuesday and next tuesday is very important, georgia is the biggest state in delegates in super tuesday. we have a real chance here to send a signal to the country, but we need your help to do it. >> ifill: and paul spent last night in virginia, where only he and romney qualified for the ballot. >> we still are winning a lot of delegates, and that's what counts! >> ifill: 419 delegates will be up for grabs next tuesday. to clinch the nomination, the republican party's eventual nominee has to collect 1,144 delegates. so far, no one is even close. as of last night, mitt romney leads with 135. newt gingrich has 32. rick santorum has 19. and texas congressman ron paul has eight. another 126 delegates are not bound to any one candidate, for a closer look at the contests ahead and what's at stake, we're joined by josh putnam, political science professor at north carolina's davidson university. he runs the political blog, "frontloading hq," and those are his delegate estimates. and "newshour" political editor christina bellantoni. christina, after last night, after seeing what romney did in arizona and michigan, is it safe to call him the front-runner again. >> i think so, yeah. particularly when you look at the map. it's very difficult for any of these other candidates to really forge a path forward because he can collect in this slow build toward having that magic number, even though it could take months and months. >> ifill: but winning delegates doesn't... winning elections, as he did yesterday, doesn't necessarily equal winning delegates. there's a disconnect there somewhere. >> yeah, there is. and i think that's what supertuesday is really going to take a look at that. it's how many states, what types of states is he able to win? can he win in ohio, which is a very similar electorate to michigan, which he was able to pull out this very small win. or is he able to win any of these southern states? will he even comp