Upon until 10 years ago the United States did not recognize dual citizenships according to the State Department site.
Countries Which Prohibit Dual Citizenship:
Austria, Belgium, Brunei, Burma, Chile, China, Denmark, Ecuador, Fiji, Finland, Germany, Iceland, India, Indonesia, Iran*, Japan, Kenya, Kiribati, Korea, Malaysia, Mauritius, Nepal, Norway, Papua New Guinea, Peru, Philippines, Poland, Romania, Singapore, Solomon Islands, Thailand, Venezuela, Vietnam, Zimbabwe.
http://www.immigrationdirect.com/citizenship_test/citizenship-library-dual.htm
Thank you for the link. I read some of the blogger comments on the african wordpress site. Interesting.