No, because their power is limited by their role in society and the organization in which they operate. Even the president of the United States has limited powers. If Obama just decided one day that the best course of action was to nuke Moscow and doubled down on doing so it's extremely unlikely he'd be able to do so. There are enough other people with careers, jobs, pension plans and common decency between him and actually launching missiles that I don't think it's credible that it would happen on a whim like that, even a persistent one. Someone would call a doctor and get the President some medication.
However, that depends on the people between the president and nuclear launch being decent human beings that care about law and order and proper procedure. You need to look at the system, not just individuals.
Alternatively, let's say someone came to power who genuinely believed nuking Russia was a good option. Rather than order a launch on the spot, what they'd actually do is gradually build a case, appoint pliable or similarly thinking people to key positions, get the launch protocols revised, engineer a geopolitical crisis by provoking Russia and drive events towards a situation in which a nuclear launch seems like a legitimate option.
This is a complete misunderstanding of US nuclear policy and weapons systems. It's designed to enable the president to launch missiles at any target as rapidly as possible, not to doublecheck or safeguard against him.
You might say "sure, but there are people who have to actually execute those orders." But give the Pentagon some credit--those are people who have been systematically selected because they follow orders quickly and without question. For example, consider what happened to Harold Hering when it became obvious that he was not one of those people.
It's rather an argument for a crafted system of checks and balances than a big government per se. The totalitarian governments, for example, are absolutely massive, and many don't even have some sort of politburo to reason in a dictator.
A counterargument would be that it's harder for a big government to change direction easily, once decided and set in motion. Wrong decisions can compound because it's easier for a large organization to stay its course, even in the face of increasing harm, as evident by the Vietnam war.
However, that depends on the people between the president and nuclear launch being decent human beings that care about law and order and proper procedure. You need to look at the system, not just individuals.
Alternatively, let's say someone came to power who genuinely believed nuking Russia was a good option. Rather than order a launch on the spot, what they'd actually do is gradually build a case, appoint pliable or similarly thinking people to key positions, get the launch protocols revised, engineer a geopolitical crisis by provoking Russia and drive events towards a situation in which a nuclear launch seems like a legitimate option.