Italy and Greece: two countries that are on the verge of economic collapse as a result of corruption, tax avoidance, etc.

Japan, Hong Kong, and Korea---three places with very strong U.S. and U.K. influence...

You're conflating a lot of things -- I'd hesitate before noting correlations to causation.

I'd consider viewing things under governmental structure, incentives, and the checks and balances in play than attributing any one culture or nation state to be some kind of paragon of virtue. Efficient governance is a luxury of first world countries, where enough people are capable and incentivized to play by the rules for it to work.

I do personally subscribe to freedom and the desire of the population for equitable governance and a level playing field for a better society, but that's a discussion for another time.

I think you are missing the point. "pervasive government corruption" is no more or less likely to occur in Asian countries than anywhere else.

Are you even looking at the map you linked to? Do you not see the Asian countries (ex-Japan) colored in reds and dark oranges, while North America, Australia/New Zealand, and western Europe are in shades of yellow? The major Western economies have scores of 70+ (U.S., U.K., Germany, France, Australia), while the major Asian economies, ex-Japan, have scores in the 20's and 30's. South Korea straddles the two, with a score in the 50's.