Global Killing: Awakening SSS-level Talent at the Beginning - Chapter 1373:

This is a world where a king is the most powerful.

The earth has entered the era of aura recovery, and human beings have started their supernatural awakening!

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

Sixty years after the global catastrophe, the Little Freeze Period ended, and the governments of the living regions began to collect land in the anarchic areas to be planned on a large scale, reorganized resources, and entered the recovery stage in an all-round way. These two decades are also called “golden Twenty years”.

This is a bright era in which new regions are rising one after another, politics is set up, capital is acting, careerists are everywhere, heroes are powerful, villains and grassroots are rising together! A young man rises up in troubled times with a full stomach of strategy, hides a tiger in his chest, and measures the world.

- Description from novelbuddy