When FDR needed to declare war on Japan in December 1941 after the bombing of Pearl Harbour he had to go to Congress to get them to officially issue the declaration. But it seems that every US president ever since has got around that provision by not officially declaring a state of war but by calling it something else.
Putin's apprenticeship was served with the Soviet KGB - a law unto itself I believe. So what could you expect?Anyway, Putin is widely believed to have killed his political opponents. No American President has done that.
US presidents normally do not murder their political opponents but boy, the same does not work the other way. At least three of them have been assassanated so far: Lincoln, McKinley and Kennedy. It seems that in the US they kill off all of their good ones while letting the rogues and scoundrils get away unpunished.