The English speaking world uses the word fascism. Seldom do those who use the word know what it means. Hitler was a fascist and he was belligerent. He was a number of bad things. Fascists are usually belligerent but fascist describes the way an economy functions. Crony capitalism is a popular term and means something close but not the same as fascism.
Leaders do no purposely become fascists, nor do they consider themselves as such. Prior to the advent of democracy, fascism had not evolved. Fascism grows out of democracy and destroys it.
The founding fathers innocently believed the biggest threat to democracy was that the masses would use democratic principles to take assets away from the rich. They were wrong. The poor and middle class do not have the intelligence or political instincts to use government to enrich themselves. True, there are programs for the poor but the rich who administer the programs gain more than the people the programs are designed to help.
Government serves only those with political power. As soon as the Revolutionary war ended, the government was used by anyone with enough political power to gain an economic advantage over all others. At first the process was not even noticeable.
As time goes on more and more people use government to rig markets and force citizens to buy products and services. With every passing day political power becomes more and more consolidated until a few folks at the top get almost all of the benefit of government. Criminals learn that with political power they can live above the law and commit crimes with impunity. In early days every appearance is that the economy is growing by leaps and bounds. It is but the number who benefit from the expansion gets smaller until the economy collapses. Businesses which initially benefited from the fascist process discover that they have lost the political power they used to count on. In time the general population becomes like automatons with their opinions and spending managed by the media and politically elite. At this point the economy can no longer grow. Often a war starts or a rebellion occurs. This is the point the Unites States is at now.
Fascism is a symbiotic partnership between business and government. Fascists do not think of themselves as fascists and the public does not believe they are being cheated.
Fascism could be avoided if a country’s constitution made it illegal for business to use government as a tool. Our tradition of using the Supreme Court to decide the constitutionality of laws is the equivalent of having a perpetual constitutional convention. The supreme court is a political institution and renders political decisions that always represent the mindset of the group with the greatest political power. There is not much chance the Supreme Court is going do support attempts to rein in fascism. All of the political power is at the top.