I want to ask a question: in the United States, do institutions like the CIA, the FBI and the National Security Agency allow foreigners to exist?

I can tell you responsibly that there are many. The CIA is the CIA, and the CIA is engaged in human intelligence. It is certainly convenient to use local people to collect information from different countries. The US Federal Bureau of Investigation is the Federal Bureau of Investigation, which is most misunderstood by China people. Of course, they are engaged in intelligence work, but more importantly, law enforcement agencies in the United States are under the jurisdiction of the US Department of Justice. The United States has judicial cooperation with many countries, such as Canada, Germany and Britain. It is normal to employ some foreign judicial personnel at the same time. For example, officers of the Royal Canadian Mounted Police are often employed by the Federal Bureau of Investigation to fight drug trafficking, money laundering and terrorism. The NSA is the National Security Bureau, which belongs to the Ministry of National Defense. This bureau also collects intelligence, but unlike the CIA, it does not engage in signal intelligence, such as spy satellites and eavesdropping. There are also many foreigners in this bureau, such as its echelon system and huge monitoring system. Seven countries around the world have large signal collection antennas, and some local people will be employed in different countries to maintain the normal operation of the system. In the headquarters, that is, the glass-walled building in Public Enemy, tens of thousands of language experts from all over the world gathered.

Of course, the most important positions will only use nationals, such as confidential personnel who manage files. In other words, an immigrant may become a general or a member of parliament in the United States, but he will certainly not be a confidential person who manages files.