There is a famous legend that has been mentioned in reliable...
There is a famous legend that has been mentioned in reliable Shi'ah books and belongs to the era of Imam Ja’far As-Sadiq or Imam Muhammad Al-Baqir. At that time the coin of Islamic world used to be minted in Rome. In this context Rome made some threats that created a problem for Muslims. At this juncture the Imam guided the khalifa (ruler) of the time. It is odd. We have seen only one or two instances where the Imams have extended cooperation to the rulers.
This is one of those occasions where the Imam guided the administration on how to mint the coin as those people did not know how to mint silver coins. So in the context of external relationships it is prohibited to accept even slight influence from the enemies of Islam. The Islamic society and the Nation of Islam has no right to establish relationships with non-Muslim world except one of dominance over them.
In other words if there is such a contact between the Nation of Islam and the non-Islamic government that results in subjugation of the Islamic nation as happened in the tobacco case you have all heard and read about, then the Islamic World does not have the right to establish such an association. Similarly the kings and Mughal Emperors of India allowed foreign countries to come and establish their companies in India; this act was wrong and against the Wilayat of Islamic World.
They should have known and everyone should know that when companies like East India Company enter their land what calamities they bring upon the local residents and establish imperialism in the veins of this great continent. The World of Islam has not been allowed to develop this sort of relationships and associations.
We should keep in mind that when we talk about not establishing relationships with the non-Muslim governments and nations it does not mean that the Islamic World should be detached politically from the rest of the world. This is a not a matter of political isolation. One should not think that the World of Islam should neither have trade relations with others nor political nor diplomatic; neither should it send its ambassadors to other countries nor accept theirs. No, this is not it.
It should maintain its liaison with others but should not have Wilayat with them; should not have bondage with them; should not have such a relationship that will allow others to have sway over the Islamic World. So the Qur'anic Wilayat has two manifestations.