Why does Yuri not mind control the president during the Soviet invasion?

During the Soviet invasion at the start of Red Alert 2, The president of the USA phones the Premier of Russia and asks what he is doing with the invasion. After some banter between the two, Yuri is shown to pick up a phone, contact a nuclear silo and tell them to not open the doors so the missiles blow up in the silo.

Why not just phone the president direct, order him to stand his men down and Russia take over the country easily?

I know this might come down to the fact if this happened there would be no game, but it just seems like a bit of a bad strategy. Is there any reason why that anyone knows of?

This video should help you will see what I mean

I think there could be pretty reasonable explanation to this. The silo explosion is irreversable action which required just short-time mind control. Mind-controlling the president on the other hand is no use. As soon as he hangs up the phone, he can cancel any order he gave being under mind control. There is also possibility that others will refuse to execute any unreasonable order given by the president (human factor).