The only reason that Korea is not a "BIG & POWERFUL country" is because of the population size. It has literally nothing to do with being civilized or intelligent. If Koreans lived in China and had the China population size, and Chinese lived on the Korean peninsula with the Korean population size, who do you think would be the "BIG & POWERFUL country"???
In this day and age only barbarians would consider nuclear warheads and militaries to be more important than wealth, prosperity, advancement, and intelligence.
At the end of the day, people are not immigrating to "Great power" of Russia, but would love the chance to get into Korea. People are trying to get into pacifist Sweden over the militarized Iranians.
Part agree, but small lands and few population is the big flaw for Korea.
The wealth and high per capita GDP can not build a "BIG & POWERFUL country" for example Luxembourg,Switzerland,Norway,Sweden,UAE etc individuals richer than United State, but they'r not as global powerful as U.S and American soft power attract more immigrants coming.
The big lands also can not build a "Big & Powerful country" for example Canadia and Australia, at least right now they have many lands but few population. It looks like both of them not willing to become the "Big & Powerful country".
The huge population is a double-edged sword. if ur government can work effectively not only feed huge ppl but also command millions of ppl work together and country development, the huge population will become a big production machine of "world factory", In the War whole country become a big ordnance factory. But if ur government fail to govern huge ppl, they will become a big burden, lack rich and poor living conditions, at most a regional power not become "Big & Powerful country".
So if I compare Russia with South Korea:
1. Russian lands much bigger than Korea it means unlimited resources and wide strategic depth. In the War Korea so easy to lack necessary resources to support military productions, and so easy to destroy major production cities and military bases.
2. Russian population bigger than Korea it means they have enough soldiers and reserve forces to go through a high-intensity conflict and brutal war. They can fight War for many years and have enough ppl for the great counter-offensive against enemy.
3. Russian military technology, specially submarine, fighter, tank, engines still advanced than Korea. Yes recently Korea develop achievements at shipbuilding industry but main at civil ships. Look at new warship serving in Korea Navy, many sub-system like VLS, radar, missiles, command system purchased from foreign West companies. Even Korea Navy owned the most powerful KDX-3 DDG in Asia, how many this big warship Korea could afford ? Building 3x, other country like Russia and China building 10x-30x domestic submarines or smaller phased array radar DDG. 21 century War is the sky fight, Korea just start developing advanced jet trainer and Russian own more advanced than Korea's aviation industry. Even Korea Airforce owned 200x F-15k, without American helps still lack of advantage on the quantity when face hundreds of Su-27, Su-30, Mig-30, Mig-29 sea.
4. S.Korea no chance in nuke War.
Well my personal opinion, S.Korea can develop as a peaceful and beautiful rich country like Switzerland but not chance in the next World War.
Anyway a stable/peaceful/strong Korean Peninsula is benefit for both Russia and China. U should pay attention to Japan islands there'r over 100million Japanese, during hundred-year of history anytime when Japan get troubles Japanese willing to transfer their own domestic contradictions to foreign wars and always the Korean Peninsula is the first target before coming into mainland, most Japanese like right-wing. Right now S.Korea and Japan r the alliance under command of U.S, but indeed Japanese loves Korean ?
Above ALL, i just tell the truth: the "Big & Powerful country" mainly depend on military power.
If Koreans lived in China and had the China population size, and Chinese lived on the Korean peninsula with the Korean population size, who do you think would be the "BIG & POWERFUL country"???
I don't think so, coz a multinational state owned more domestic natinoal troubles than a single-national country (P.S Russia and China, U.S all r multinational states), more population size and more multinational communications. The Korean style would be useless when ur people govern China lands, i mean Korean won't face only Han race also need to make contact with other 55x ethnic minorities (some national minorities size > 10million). Korean ruled korean peninsula for thousand year but today it's still a single-national peninsula, u lack enough experience to govern a big lands with many ethnic minorities. China spent one thousand year absorbing other 55 ethnic minorities and growing, Russia spent hundred years absorbing 100+ ethnic minorities, U.S also spent 200 years absorbing foreign immigrants (we all knew American had stains on history, murdered American Indian, civial war for black slaver, equal rights for American Black).