But a deal that does not meet its basic expectations, no deal at all, or an endlessly strung-out process while Iran advances its programme, will place its decision-makers back on the horns of a dilemma: whether or not to intervene to avert what it considers the most serious threat to its national security.
But a distinction should be made between situations like Kosovo and the floods in Mozambique: it was important for the United States to intervene in Kosovo not only to avert a humanitarian disaster but also to send a clear message that aggression would not be tolerated.
"This strategy's four actions areas – tackling feral cats, providing safe havens for species at risk, improving habitat and intervening to avert extinctions – are commendable," said Kelly O'Shanassy, chief executive of the Australian Conservation Foundation.
The government said at the weekend that it would intervene in the BA dispute in a bid to avert a series of strikes by cabin crew.
In March, the Federal Reserve and other regulators intervened to halt the collapse of Bear Stearns, arranging for its sale to JPMorgan Chase to avert a cataclysmic chain reaction in the credit default swap markets.
Trying to avert a strike, leaders of several unions have asked Mr. Pataki and Mayor Michael R. Bloomberg to intervene to pressure the M.T.A. and union to reach an agreement.
Last month, when the White House sought to avert a divisive Republican Senate primary in Minnesota that could upset plans to challenge Senator Paul Wellstone, a Democrat, Mr. Cheney was asked to intervene.
Last year, when the White House sought to avert a divisive Republican Senate primary in Minnesota that could ruin plans to unseat Senator Paul Wellstone, a Democrat, Mr. Cheney was asked to intervene.
