'blood unity' - that's a good way to describe fascism.
Mussolini described it as 'the union of government and corporate power'. Corporate in the sense of corporate bodies - which includes things like trade guilds, etc. The Doctrine of Fascism
is also pretty telling. Describing it as 'socialism in reverse' seems pretty apt - businesses that ally with government get more benefits than those that don't, and they become effectively unified.
Fascism has a set of behaviors associated with it
- Patriotism is the core virtue, at least while they are in power. "My country, right or wrong." and other jingoistic phrases like that.
- As mentioned, fascists are heavily militaristic.
- Fascists have an ends-justify-the-means attitude about attaining power. As the Doctrine states, fascists don't believe the mere fact of being in the majority should accord one any rights. This gets taken to an extreme.
- Like many totalitarian regimes, they are highly anti-intellectual. They will attack and demean scientists, teachers, education in general.
- A major difference between fascism and governments that can collapse into totalitarian regimes (e.g. communism) is that fascism is at its core totalitarian - the philosophy is in and of itself totalitarianism. The citizen is to be subservient to the state while they are in power.
Communism is built on the idea of the common ownership of the means of production. As described by Marx, it cannot exist until technology and production progresses to a point where labor is so productive that it's possible for a few people to support millions. It's not meant, per Marx's original declaration, to be something that is technically feasible at the current moment.
You can think of Elliquiy itself as a microcosm of this concept, although Marx never could have envisioned it. You take advantage of the services it provides, and the volunteered labor and resources of several dozen people supports entertaining four thousand. And I'm working on making things an order of magnitude more efficient and then some.
That is to say, Marx took technological and industrial progress to a very logical conclusion, even if, in order to apply his precepts now, they'd need to be re-thought.
Serious actual attempts at communist governments are limited by a few factors. Until the rise of computing power, efficiently allocating resources on national scales was impossible. This was Ludwig von Mises' argument, and it still holds true, somewhat, but it was always far less relevant compared to the bigger problem - which all governments face. The Soviet Union didn't collapse for a lack of capitalism, it collapsed because it was overspecialized in heavy industry.
In order to have an honest government, you need transparency, and an ability to act on the transgressions revealed by that transparency. When 'the government' owns everything meaningful, one or frequently both of these requirements can become extremely fragile. While the US government has major issues with lack of transparency, corruption, and means of redress, we have a fairly strong constitution, even by western standards (not all countries are granted the right of free speech), and capitalism, while it certainly sees abuse, means that it's really hard for one body to obtain 'all of the power'. Somewhere, somewhen, a person can rake in a few billion and go on a moral crusade of their choosing.
As for socialism... you'll really need to be more specific, I'm afraid.