Seoul vs. South Korea

As you know, in English writing, capital cities represent their respective countries. For example, instead of saying "the United States decided to do something," you can say "Washington decided to do something."

However, make sure to use a country's capital only when the national government is doing something on behalf of the entire nation. Otherwise, your sentence could be misunderstood as concerning the city government or the capital city itself. Take a look at the following examples.

미국의 지적자본이 경쟁국들의 지적자본보다 뒤쳐짐에 따라 우리의 명성이 위험에 처해있다.

• As Washington's intellectual capital lags behind that of its competitors, our prominence is at risk (x): You are not talking about the intellectual capital of federal government officials or the city of Washington, D.C.
  
• As America's intellectual capital lags behind that of its competitors, our prominence is at risk (o) (Wall Street Journal, June 20, 2009)

영국의 한 저명한 기후과학자는 영국 정부의 기후 변화 정책이 위험할 정도로 낙관적이라고 경고하였다.

• A leading UK climate scientist warned that the UK government's climate change policies are dangerously optimistic (o) (Guardian, June 23, 2009)
• A leading UK climate scientist warned that London's climate change policies are dangerously optimistic (x): London here could mean either the city government of London or the UK government, depending on the context.