Does anybody think that what's happening off the coast of North Korea, with the resulting threats from China, is scary in any way?

The US is doing a naval exercise off the coast of North Korea, and North Korea has issued a strong threat of nuclear retaliation to try to deter the US from doing the exercise. China has also threatened the US as a result.

Does anybody think any of this is really scary?

Why is it necessary for us to show our muscles to prove a point? or am i incorrect?