Many organizations list international petitions as a way to influence decisions by governments. Amnesty International's German site explicitly states that such "urgent actions" are an effective way to save lives. As evidence, they state that for 35% of urgent actions run in 2007, positive results have been achieved; however, there is no indication of whether those positive results were a consequence of the actions, or would have occurred anyway.
Is there any evidence on whether international petitions, either on-line or in written form, have an influence on government decision-making?
I would like to point out cases that might be special in that the petitioner has an obvious influence on the decision-maker. This might be because he is a voter writing to his own government (explicitly or implicitly threatening note to re-elect it unless it does what he wants); or because he is in a position to make other threats (e.g. of attacks such as in the recent The Interview events). I am interested in other cases: Can I, as a non-citizen, influence decisions made by the governments of Iran, Russia or the US?