What it is: Technically, blowback is the reverse movement of gases in a boiler or engine or when firing a weapon. The USA's Central Intelligence Agency (CIA) first used the word, among themselves, to refer to unintended - and unpleasant - consequences of American foreign policies.
What it means: A 1997 report in the USA said 'Historical data show a strong correlation between US involvement in international situations and an increase in terror attacks against the US.' It's also possible to look at things being done right now and work out how they could lead to 'blowback' in the future - just as people forecast that difficulties and violence would result from military attacks on Afghanistan in 2001 and Iraq in 2003. Governments have to be persuaded to think more carefully about potential future disasters that could be created by their decisions.
Think about it: In some ways the worst kind of blowback is the result of actions the general public know nothing about. For example, the CIA and other intelligence agencies have carried out secret operations to make events go their government's way - and have made changes all right, but not always the ones they meant. Some of the hostility against America has been caused by the results of such undercover activities. So what should be done? We can't change the past or see into the future, but maybe the present could be adjusted to give a peaceful future a better chance. Ask openly for open government. Call for cutting the powers of the military. Create a world where secret intelligence is out of date or even impossible (the internet could help here). Anything else we could do?