Crime or Saving grace?

Stephen Collinson's "GOP Warns Iran and White House" discusses the letter 47 senators signed and sent to the Iranian government regarding the nuclear program (Link to article).  47 Senators of the GOP signed a letter to thwart Obama's deal-making with Iran, something many, including most of the Democrats, are calling "unprecedented."  The letter informed Iran that the deals Obama is planning are possibly useless because he will be leaving office in a little less than two years. 

This is huge.  The GOP is looking for a total shutdown to the possibility of Iran getting nuclear weapons, and some feel Obama is realizing they will create weapons anyways, therefore offering them money for limiting different uses for the nuclear program.  The question at hand is did 47 senators break the law?  It is unprecedented, but since I don't follow this much, I cannot say.  But I do know one thing: Iran with nukes = a very bad day for the United States of America.  I think we all know one of the first thing Iran will do with a nuclear weapon - sending a "care" package to either the US or Israel.  This needs to be stopped as soon as possible.