Perfect little example today of how who gives the briefing shapes the way the news is written. Referring to the European diplomatic efforts to stop the Iranian bomb program (those efforts which were supposed to show the benefits of the European capability for nuance and multilateral negotiation) we get this accusation:

America has hobbled an effort by Britain and other European countries to persuade Iran to freeze its nuclear programme.

What have the Americans done?

Senior officials said privately that the US would not offer economic or political concessions to woo Teheran…[…]…But many of the benefits that Teheran seeks – advanced technology,
investment in its oil industry and greater international acceptance –
can be provided only with US agreement.

What would appear to have happened is that the European side offered things they could not deliver in the negotiations, and are now crying foul when the US restates its earlier position, that the US would not offer these things.
Doesn’t sound like America hobbling anything, sounds like European negotiators making a bad deal.
As you can see, very important who briefs the reporters on the correct line to take in these matters.