Power projection is not solely military.

The USSR collapsed when it could not compete economically with the West and when it could not monetise the vast resources within its territory due in large part to obstruction of pipelines and trade by the west. the USSRs adventure in Afghanistan was a failed attempt to enable export of vast oil and gas resources in Khazakstan which could have been pumped out and exported via Afghanistan, Pakistan and Iran if Afghanistan had been conquered.

Chinas per capital incomes are rising and its economy, in terms of manufactured exports now exceed those of the US- China has already won the trade war both in terms of efficiency of manufacturing and in terms of buying power of commodities. China is on the rise and is building the global strategic trade routes via belt and road in a direct challenge to US hegemony- nowhere is it more obvious that 'free trade' is a nonsense- tariffs and sanctions and ultimately war are always on the table and they are imposed by nation states.

N and S Korea are still technically at war- WW2 never ended for them. They both exist as power projections of the US and China. Egypt is a military junta backed by the US. Without US support it would collapse into sectarian chaos.

Iran now only remains viable as a subservient tribute state to China- exporting its oil to China at a discount rate because China can and does ignore the US sanctions. Iran is a proxy war power projection and economic tribute state to China- its survival is dependent upon Chinas patronage.

Power and trust and the rule of law with a good constitution is explicitly nation state power projection internally and often externally! Look at the US and its claims to be exporting 'democracy' when in reality it has expanding its banana republic tribute states from its own continent to a global reach- a global reach of power projection...one that is unparalleled in history...and saturated with hypocrisy and self serving duplicity.

Study the real world outside of your ideologically simplistic Libertarian 'free market' dogma that ignores how the real world economy and power dynamics actually function.