Political use of the term "blowback" first appeared in the CIA's internal history of the 1953 Iranian coup. Orchestrated by Britain and the U.S., the coup replaced the democratically-elected Mosaddegh government with the Shah. The term proved most appropriate as the big power mischief ultimately led to the Iranian Revolution and alienation of Iran from the West, essentially the opposite of the intended consequences.
Judging by two recent examples, overthrowing dictators can equally result in some nasty blowback. The usual suspects, Britain and the U.S., led the invasion of Iraq which successfully overthrew Saddam Hussein. The theory was that with the overthrow of Hussein, the Iraqis would shower their liberators with candy and flowers, embrace democracy and become good friends with Israel. It didn't quite work out that way. The invasion resulted in the deaths of tens of thousands, millions of refugees, massive destruction of the country, and a nation declining into chaos. The Kurds have taken control of their ancient lands in the north, Sunni insurgents attack Shias and the brutal Islamic State of Iraq and the Levant has seized control of several major cities in the northwest. The country may not survive.
Every action can have unintended consequences, but it seems that when Western countries interfere violently in other people's business, the consequences are all too often tragic. The West can and should do a lot of good in the world, but it might be advisable to confine its contributions to more constructive instruments than bombs.