I'm almost sure Adams didn't think he was joking. He was just expressing it through a joke.

Funny quote and all (no sarcasm intended) but I don't think it's fair to imply that, if future wars are bloodier than the past, it would be because we lowered barriers to communication.

Being diplomatic can be about being a communication filter.

Do you have an example of a bloodier war than the World War 1 and 2?

Well, there was the time that the Krikkit decided to wage war on the entire universe for 2000 years - I believe the estimate was about two grillion casualties.

You might like https://en.wikipedia.org/wiki/List_of_wars_by_death_toll

Though you might want to look at your wars by death toll as percentage of total population?

WWII wasn't the bloodiest conflict when you adjust for world population at the time. E.g. the Mongol Conquests or An Lushan Rebellion probably killed more.

In case you’re being serious, Douglas Adams was an author of comedic fiction and the babel fish is from his Hitchiker’s Guide to the Galaxy book and allowed different races from different planets to communicate with each other.

Trying to compare real world history with fictional possibilities is non-sensical.

No, but Second Sino-Japanese War, Taiping Rebellion and Transition from Ming to Qing are comparable.

In terms of body count, those still win, because Mutually Assured Destruction keeps giving people pause. But the Internet has turned into a machine for goading people into making a mistake, and it will only take one.

Meantime, thus far it's used just for local genocides, like Myanmar.

I'm repeatedly surprised at how many people dont seem to get that most scifi is deliberately a reflection of issues that already exist in our current day society.

Like that is what makes the jokes in hitchhikers guide funny, and why the matrix is one of the most poignant narratives in pop culture... black mirror is real life taken to poetic extremes, it's not a coincidence that zuck's metaverse gives off "black mirror vibes", that is the specific intention of black mirror

That joke most certainly was a reflection of society, but I think it's different from the way that joke reads today (and out of context).

HHTG channeled the malaise and confusion of the 1970s, driven by nuclear war and economic downturns. (OK, a bit like now...) HHTG responded to that nihilism with pessimism on one side (Ford) and absurdism on the other (Zaphod). A lot of pleasures (sex, drugs, and rock and roll) were feeling hollow, and all Arthur (the prototypical Englishman) just wanted to hide and be comforted.

That joke certainly reflects a pessimism that is persistent in all societies, that every good thing must also have a downside. I took it out of context to highlight the communication aspect, something that I don't think was especially on Adams' mind -- though it would be only a few years before a communications revolution.

I think Adams' would take credit for pessimism being right -- usually a safe bet.