A few days ago, after the post of "Afghanistan purchasing second-hand 737", some friends asked why Afghanistan didn't buy aircraft from China. 

China now has a domestically made ARJ21-700, and the large aircraft C919 is scheduled to be put into commercial use by the end of the year. 

Why not sell to countries like Afghanistan, Iran, North Korea and Cuba, which have long suffered from a shortage of new aircraft under U.S. sanctions?

There are rules about this. Because planes like the ARJ21-700 and C919 use a lot of American components and technology. For example, the main engine

 is made in the United States. So under the agreement, these products cannot be exported to countries that the United States has restricted. Planes are not

 suitable to be sold secretly. If the US knows about the "supply cut", our aviation industry will be in trouble.

But Russia is not subject to this restriction. Russia's homemade aircraft use its own engines and avionics, which the United States cannot do anything about. 

Now north Korea and Cuba are all Russian planes like Tu-204, Il-96, etc., which is out of the hands of the US. 

Boeing also made a commitment to the U.S. government when it exported planes to China that they would not be diverted for military use. 

But when relations are good, the U.S. government turns a blind eye. From our side, what we do with the plane once we get it is our business. 

So if we actually bought two 737s and turned them into electronic surveillance planes or something -- there's no way the U.S. government 

would ban Boeing from doing business with us because they have to make money.

The US is indeed a bully, but it has the core technology and there is nothing it can do about it now. The quality of our products is sometimes not perfect, 

the J-7 could be exported to many countries, but the J-10 has not been sold so far - this kind of military aircraft can not be exported to the United States. 

Unlike an airliner, this one has no parts from the other. 

However, the United States generally does not care about "small aircraft", China's New zhou60 and YUN-12 can also be exported. A shipment of 

Y-12s was delivered to Nepal this week, although it was reported last year that Nepal had discontinued the aircraft. Both the New Zhou 60 and y-12 

use American engines (made by Pratt & Whitney Canada, a subsidiary of Pratt & Whitney USA).

To say the least, the ARJ21 and C919 can be "exported" if the US agrees in order to "jointly develop the market". But if America's Federal Aviation 

Administration (FAA) does not issue a "certificate of approval", many countries may not be allowed to land or even overfly their airspace. Not only would

 it be difficult to operate, but delivery would be limited, which is why Chinese aircraft still need FAA certification. 

Afghanistan is our neighbor, and even if the FAA doesn't grant it, if Afghanistan wants to, it can certainly get a deal as long as the United States turns a

 blind eye. There's only one problem: The price of our domestic aircraft is often too high, like when the Santana sedan sold for 180,000 yuan. The price 

of the ARJ21-700 is estimated at $38 million, but the market value of the used 737-500 currently procured by the Afghan government is only $2.5 million. 

That's a big difference.