This is supremely clever propaganda. A former PLA senior colonel, Zhou Bo, writes for the once balanced SCMP (what a fall!) about the "inevitable decline of the US" and wonders if it will be peaceful.

"inevitabile decline",
a) the "inevitability" itself is removed from the central focus, that from any challenge or question.
and
b) the old question of whether China's rise (again considered inevitable) will be itself be peaceful is completely ignored.
Interestingly, however,

he also states that "China’s rise so far has been peaceful" - only "so far", mind.
Let's ignore for a moment China's actions against the Filipinos in the South China Sea, its provoking the Japanese SDF in the East China Sea or its initiating a major confrontation along the

disputed boundary with India in 2020. Zhou is signalling that if the US isn't going to be peaceful, don't expect China to be either.
"the Pentagon’s unabated military interventions after the Cold War have reduced the US’ national strength – a point few seem to disagree with now"

No definition provided for "national strength". Just a bald assertion. Accept it, swallow it - as Zhou rushes quickly to the next point
"when a democracy is in decline, it may become vitriolic and violent" - forget that authoritarian states are at all times vitriolic and violent