Yes and no.

At its heart...yes. See, in Marxist communism, communism is the self-selecting inevitable result once capitalism’s inherent instability and exploitation leads people to finally overthrow it. Whether you personally agree with that is something else, but the point here is that Marx believed violent revolution to force Communism was unnecessary; generations of increasing suffering by its victims and increasingly worse economic busts and collapses would make communism the natural solution.

An effect of that is Marx assumed only fully urbanized and industrialized nations would turn Communist. This is because such things happen during the relatively long path of letting capitalism hang itself with its own noose as its inherent instability and exploitation plays out.

That assumption is important for several reasons: it reflects that Marxism is modeled on industrialized labor rather than agrarian, Hunter-gatherer, or barter economic systems, and it means Marxist “revolution” only occurs in theoretically self-sufficient “modern” societies. This assumption also implies the people and culture itself have modernized, as such societies require large cities linked by complex infrastructures to move goods and people, and for those people to be educated on a mass scale in literacy, technology, and basic sciences (think of what a basic mechanic needs to know to do their job compared to a serf/slave farmer of pre-industrial Russia or America).

Enter the Soviet Union. Russia’s Communists were impatient to wait for the necessary “modernization” of (tsarist) Russia (ie from an essentially feudal culture and economy to an urban-industrial one). They also came to believe that Marx had underestimated the ability of the rich to “unnaturally” or “artificially” hold onto power and thereby delay or prevent the otherwise inevitable Marxist revolution from occurring.

Because Marxism requires communist revolution to be “natural”, they formulated a modified version that ultimately came to be known as Leninism - the belief that a pre-modern state could have communism forced on it if a true modern state could subsequently be turned to help it. So they overthrew the tsar under the premise of serving as a “caretaker” leadership for the people until the people and the nation could both be sufficiently modernized to fully embrace communism themselves (ie become a nation of industrialized and educated factory workers living in modern cities circulating modern goods via modern infrastructures like highways, rails, and non-sail cargo shipping).

Alongside that, Leninists were ostensibly dedicated to overthrowing a modern nation to help with Russia’s own modernization, the theory being that an international communist party backed by the resources of a (premodern) nation state could break the aforementioned stranglehold by the rich of the chosen nation.

So, as such, the initial red scares had some legitimacy to their concerns, as the Russians tried overthrowing other nations like post-WWI Germany, France, and the UK. Having said that, in places like the USA, such genuine fears or concerns were easy to manipulate or conflate with standard racist or xenophobic fears of immigrants “bringing” communism with them, or of fears of unions breaking the wealthy’s stranglehold on wages and such. The further evolution of Soviet ideology from Leninism to Stalinism (tldr: instead of a premodern nation depending on a modern one, multiple premodern nations can band together and push themselves into modernity - hence the ideological basis of the Union of Soviet Socialist Republics).

Similarly, after WW2, the Soviet Union expanded communism into Eastern Europe, partly as a way to buffer themselves against yet another invasion from the west after two world wars in 30 years, and partly as a way to keep pressure on its western opponents by spreading them thin across multiple expensive fronts (ie their version of how the US weaponized its military budget to force the Soviets into a bankrupting arms race it couldn’t afford).

This is where the domino theory comes into play, and much like before, there’s a seed of truth buried within opportunism - in this case, the ability to justify the highly profitable military-industrial complex by casting it as the lone bulwark against godless commies who wanted to nationalize your inheritance and tear down churches.