The Center of Mosque Studies - There are two kinds of infiltration: one is individual infiltration and another is systematic or network infiltration. There are many examples for individual infiltration. Allow me to explain: Imagine that you have established an organization in which you hold a responsibility. Now, they send someone to your organization who has disguised themselves by wearing a mask. You assume that they are a friend, while they are not. They only appear as a friend so that they can achieve what they have set out to do. Sometimes, their goal is to spy--which is the least important goal. The least important task is spying and gathering intelligence, in other words. But sometimes, they set out to do something that is more detrimental than spying. They change your decisions [or outlook]. You are an official [of the State], you make important decisions. You can achieve great or efficient outcomes, but if you make a turn towards a specific direction, this could be to the advantage of the enemy. They show up and deceive you into changing [your direction] to their benefit: this is decision-building and it has been witnessed in all organizations.
This [Decision-building] is not particular to political organizations. Seminarian, religious, and other such organizations have been exposed to this [tactic] as well. The late Sayyid Hassan Tahami – who was a great religious scholar in our country and resided in Birjand – once left to Birjand to live there. He was a great mullah; and if he had stayed in Qom or Najaf, he would have definitely become a 'Marja taqlid' because he was a very wise man. He once narrated a story for me in person. He said, “During the time when the Iraqis were fighting against the English – in the year 1918, which is approximately one hundred years ago – one of the Marja taqlids of that time had a servant who was a very good man. He used to speak to the clergy in a very warm and friendly manner, and he had a friendly relationship with everyone.”--The late Tahami used to mention his name, but I have forgotten it. He continued, “Later on when the English achieved victory and occupied Iraq, Najaf was the last city that they occupied. Then the clergy were informed that that servant was an English officer!” The late Tahami added, "I did not believe it." I said, ‘Is such a thing possible?'
After that, he said: “We were walking in the Hovish Market – a well-known market in Najaf – and I saw that seven to ten English officers were approaching us on horses. At that time, they used to come and go on horses. I saw that an officer was leading them. I moved aside so that they would pass. When they reached me, I saw that the officer who was leading them on his horse said, 'Sayyid Hassan, how are you?’ I looked and saw that he was the fellow who worked as a servant for a Marja taqlid. We used to see him for many years!” Sometimes infiltration occurs just as it did in this story. It is on an individual level. They penetrate someone’s house or some organization. And there have been many such cases in political organizations as well. Today, too, such a thing may exist which is, of course, dangerous.
Ayatollah Khamenei, Nov 25, 2015