Ukraine is under total control from Washington [Deep State], so it's they who make a decision who is and will be president of Ukraine: Poroshenko, Saakashvili, Timoshenko or some other clown.
I'm not sure about this completely. If Poroshenko was totally controlled by the US, Ukraine would break up all relationship with Russia. But now we have, on the one hand, official statements of Ukraine about the invasion of Russia and thousands of Russian soldiers in the Donbass, and the other - Russia is the most important trading partner for Ukraine, hundreds of thousands of Ukrainian citizens go to work in Russia, singers and artists from Russia go on a tour of Ukraine.
Can you imagine something similar in 41-45 in the relationship between the USSR or the US with Germany?
And I think that Putin (or Russia) has influence on Poroshenko and Ukraine in general. Because, in my opinion, Ukraine could already win in the war with the East of Ukraine, Ukraine has a greater military potential, has more population and even with Russian military supporting, the Donbass has a small chance against Ukraine.