Would a developer of safety-critical software try to anticipate all potential problems ?

Cadbury or Cadbury Schweppes or other producer of canned drinks would notice that sometimes the automatic canning machines malfunction. So they would train special staff to try to notice. The equivalent of this can happen in an organization supposedly producing safety-critical software. But I don’t think an organization will have trained itself to notice.

Why do the US and the UK still interfere in the internal problems of other countries?

when doing that breeds hatred and extremism ,the result of which is terrorism attacks on their nations http://uk.news.yahoo.com/22/20100104/tts-uk-yemen-ca02f96.html please excuse any spelling mistakes /grammatical errors as English is my third language and one i use only rarely your patronising attitude is uncalled and of no value i do NOT live in a third world country [...]