Fischer was always very eccsentric and rude, his anti-american views didnt start until he got indicted from disobeying a direct order from the US Department of the Treasury that he should not violate the embargo. This is also when he began expressing his anti-semetic views too..
In themans defence though, The guy believes that everybody is out to get him and that everybody is stealing from him (especially jews)... he is a paranoid delusional at the least if not a paranoid schitzophrenic.....
here is a website that has all has all his radio interviews and alot of his personal correspondence of his over the last 12 years, from what i understand this site is ran by fischer by proxy thru a friend. If you read some of his letters (especially the ones to the executor of his sisters will) you will notice he is slightly off kilter... and if you take the time to read all of them (like i did), I think you will see he is not a healthy person.
http://home.att.ne.jp/moon/fischer/