What country operates underneath socialism?

The countries that still have socialism is Sweden and Canada.

Edit:

While both Sweden and Canada have socialist aspects within their forms of government, so many other countries have more obvious aspects or socialism as part of their governmental structure.

All Scandinavian countries work withing a social democratic frame, much like Sweden, which means that despite capitalist opportunities, they have a strong welfare system, providing a safety net for people who are out of a job. As the third pillar of said social structure, these countries have policies to ensure that no one can exploit the system, and people are required to actively seek employment if they're healthy and otherwise able to work.

Actual socialist states, with very scarce (if any) capitalist aspects include North Korea and Cuba. These countries are normally considered Communist, and while this is the common assumption, no actual communist country (as described by Karl Marx) has yet existed, and the countries which have claimed to be communist are in fact socialist countries with emphasis on government control.

Given that no modern national government is a "pure" anything, all nations have some set of laws which are Socialist in nature. For example: the United State's Social Security system is extremely socialist. The U.K.'s National Health is also socialist. France's worker rights laws are socialist. Germany's national conscription laws are socialist.

Everything is in degrees - it's not a black or white issue.