How many countries have a red, white and blue flag?

Australia, Cambodia, Chile, Cook Islands, Costa Rica, Cuba, Cocos Island, Czech Republic, Dominican Republic, France, French Guiana, French Southern and Antarctic Lands, The Faroes, Guadaloupe, Holland, Heard and Mcdonald Islands, Iceland, North Korea, Laos, Luxemburg, Mayotte, MArtinique, Nepal, Netherlands, Netherlands Antilles New Zealand, Norway, Panama, Puerto Rico, Russia, Slovakia, Slovenia, Samoa, Taiwan, Thailand, United Kingdom, USA.

http://www.flags.net/indexz.htm

Going by member states of the United Nations, and counting only those flags which have all three colors -- red, white, and blue -- and no other color at all, we find twenty:

Australia
Chile
Cuba
Czech Republic
Democratic People's Republic of Korea (a/k/a North Korea)
France
Iceland
Lao People's Democratic Republic (aka Laos)
Luxembourg
Nepal
Netherlands
New Zealand
Norway
Panama
Russian Federation
Samoa
Slovakia
Thailand
United Kingdom of Great Britain & Northern Island
United States of America

If we count Taiwan, which is not a UN member, that would bring the total to twenty one.