Our Government’s desire to please western Europe is one consideration behind the reluctance to take down Iran’s nuclear facilities and military forces. Western European nations (and certain people in our government) are full of wishful thinking about Iran targeting Israel exclusively (which thinking Iran continues to support).
Iran is befriending the Saudis and will soon control the Middle East after mounting nukes. Then Iran will target England after having installed many more guerrilla cells there and in the USA.
Iran is seen as a major threat by the Saudis. There is no love lost between the House of Saud and the mullahs. And the Saudis have much larger proven oil reserves and produce twice as much oil and have the capacity to produce three times what Iran produces. There is no way the Saudis would accept Iranian control over the Middle East. The Iranians are not Arabs and they don't share the same language or culture as Saudi Arabia. We will not let Iran take control of the Middle East.