The answer to the title is yes, yes indeed. While the nations
aren’t overtly terrified at the sight of America, they’re still nonetheless
wary of him. From their perspective, what’s worrisome about America is his
youth and impulsivity. Now add the fact that he’s one of the leading powers in
the world, and you’re in for some destructive outcomes.

What you’ll see is that America is often equated to a child
given how he had been isolated from the world after gaining his independence. He’s
unpredictable, naïve and bossy. In other terms, he’s inexperienced, and this
leads to a growing sense of wariness and caution among the other nations.

It’s like handing over the reigns of the world to a toddler.
They may have good intentions, but only end up creating an even bigger mess than
before.

This fear of America, then, is often the result of how ridiculous
and childish some of his ideas are. England even states that America has a “flawed
sense of reality.”

Again, given America’s dominant position on the world’s stage,
this isn’t something you want to see in a leader.

Here, America’s ideas are perceived as “nightmarish.” To be
fair, his world defense plan was to construct a ranger squadron, whatever that
means. 

Either way, notice how he’s also referred to as a “brat” and “child.”

This child-like imagery comes up in how America interacts with
the other nations too. In that same meeting regarding his squadron defense plan,
America asks for a vote to be taken on it. What’s important here is that when
he offers the possibility of other nations disagreeing with him, he snaps a
bundle of spoons.

To me, that seems like an obvious intimidation tactic of someone
who is incapable of hearing alternative opinions. That said, I want to point
out how well child development patterns fit in with America’s characterization.

Children are inherently egocentric until about 6-8 years
old, as they lack the capacity to think outside of themselves. They only focus
on their own personal world and bubbles of fantasies before eventually
realizing that there’s a much larger world out there. Please note that this
egocentrism is not intentional; they just haven’t matured yet.

Still, this panel clearly illustrates that America believes himself
to be the only “player” [in the game of life].

America’s egocentrism for the most part is unintentional.
His isolation has made it hard for him to think from the perspective of others,
as he had previously grown accustomed to only looking after himself. That’s
where the “not being able to read the atmosphere” running gag likely comes
from.

However, as seen with the spoon incident, America is more
than capable of reading the atmosphere when he wants to if it means getting
what he wants…

…and that’s often other nations agreeing with him. Pay
attention to how uncomfortable South Korea gets here when claiming that he
agrees with America. Even more important is how in the panel above, South Korea
had no qualms in disagreeing with Japan.

No doubt, America is
bossy. Said bossiness and desire to get his way all the time is what’s
intimidating to the other nations.

Another display of this child-like bossiness would be when German-occupied
France and England are having an argument (big surprise), only for America to
step in and declare that he’ll decide on whose opinion is right.

There’s a bit of a discrepancy in the translation, but this
version has France say, “America, you scary boy!”

Meanwhile, my print version says, “What a frightening child,
you are!”

Regardless, both convey the same message. America does in
fact scare the other nations, sometimes.

One last example would be Netherlands warning Isolationist
Japan of America’s impending arrival. Once more, you see America’s youth being touched on.
Likewise, this youth is formulated as a reason of warning and caution.

With all that in mind, and for transparency’s sake, I’ll end
on this note: While America does often make the other nations feel uneasy, he’s
also frightened very easily himself.

Whether it’s ghosts, occasionally Russia, or sleeping alone, America is
possibly and ironically one of the biggest fraidy-cats in the series.