It should be appreciated that if the arrangement on Iran's nuclear program collapses after being so patiently negotiated, and successfully implemented since 2014 despite the intense opposition of Netanyahu's Israel and its American loyalists in Congress, it would be widely perceived around the world as a huge setback in the search for regional stability and the struggle to prevent any further spread of nuclear weapons.
After the Second World War, facilitating the establishment of the UN and aiding the reconstruction of Europe, the United States was widely viewed, at least in the West, as a benevolent hegemon. In the non-West, the US was often perceived as a supporter of the colonial powers in their struggle to maintain control over their colonial possessions, and was viewed far more critically, especially by emerging elites that were more inclined to socialist development paradigms than to the capitalist ethos favoured by Washington.
