What the latest (un-)diplomatic row on Iran's nuclear program has shown is not just that, as I said earlier, the USA seems dead set to attack Iran no matter what, but that it's also dead set to sabotage everything that Brazil attempts. This was already very clear last year with the coup in Honduras and the de-facto annexation of Colombia, as well as in the most strange case of the US invasion of Haiti on the pretext of the earthquake.
According to Raúl Zibechi (La Haine[es]) this is all part of a growing confrontation between the USA and Brazil for influence in Latin America and around the World and therefore not really unexpected, not even by the Brazilian government.
For Zibechi this confrontation is anyhow centered at the Amazonia region and the control of South Atlantic oil. In other words: the USA aims to control Brazil as it used to do in the past. As reaction Brazil is building up for the unthinkable: a war with the greatest global power ever, a war they cannot afford to happen... or to lose if it does happen.
For that reason the Amazonian military region is seing its manpower doubled, the Army has grown 30% overall and new naval and air equipment is being added to the nation's military. All purchases include clauses of full technological transfer and none of them includes US-made material, but rather Russian or French. The goal is to create a Brazilian national military-industrial complex that does not need to rely too much on foreign imports.
Eventually Brazil will have to get nuclear weapons, of course, if it wants its dissuasive power to be effective. The National Defense Strategy of 2008 clearly speaks of the need to "develop and dominate nuclear technology".
In any case it is not something that affects only this or that party: all Brazilian media is rallying around Lula on these matters and that is because it is a matter of highest national interest that goes beyond classes or political parties.
With a different viewpoint and emphasis on China's and Russia's discreet role on the Teheran agreement, it's worth mentioning Pepe Escobar's opinion at Asia Times Online, where he quotes the Chinese military genius Sun Tzu: Allow your enemy to make his own mistakes, and don't correct them. For Escobar, it is clear that the USA has made a great mistake by sabotaging this agreement so bluntly, what can only harm Washington's power and prestige (even more) and get it confronted with more and more regional powers, not just Brazil but also hyper-strategical and again self-confident Turkey and who knows what else.
Again it seems that, much like Charles V and his son Philip, the US Empire is embroiled, more often than not willingly, in way too many fronts, wasting precious economical resources in a megalomaniac attempt to control the whole World in a self-defeating strategy of total global domination (as defined by Brezinsky and camarilla) that is even more absurd now that it was in the 16th century. Because now we know that total control is plainly impossible, a mere error of imperfect and too arrogant thought.
See also: The geopolitics of today (or 'BRICs are heavy'), for a broader analysis at Leherensuge, and this other analysis by Raúl Zibechi at Voltaire Net, this time in English.