US President George W Bush announced Rumsfeld's resignation today, a day after the Democrats triumphed in congressional elections fuelled by widespread unease over the Iraq war.
Former CIA director Robert Gates will take over running the Pentagon.
Mr Howard said he, personally, liked Mr Rumsfeld but understood the reasons for his departure.
"As a result of the vote in the congressional election, it was obvious that the president decided that (as) a gesture acknowledging the unease that some people feel about the way the operation is going in Iraq that he had to do that, and I would see Rumsfeld's departure very much in that context," Mr Howard told reporters.
"I think we have to take a little bit of a reality check. Clearly the president has reacted to the vote - obviously he has, and that is sensible - but his reaction does not amount to a fundamental change in direction."
Mr Howard was not briefed by the White House about the move, but said he would discuss it with Mr Bush over lunch in Hanoi next week at the Asia Pacific Economic Cooperation summit in Vietnam.
"I will be telling him that Australia's view is that it would be against everybody's interests, except the terrorists', for the coalition (forces) to leave (Iraq) in circumstances of defeat," he said.
"I am sure it is his view and I am sure it is Mr (British Prime Minister Tony) Blair's view."
Mr Howard said there were other reasons behind the US election results, including the string of budget deficits run by the Bush administration.
"There is a measure of gesture politics in what the president has done. I understand that, and a tough bloke like Rumsfeld will understand it as well," Mr Howard said.
"My reading of the situation is that ... although they are clearly looking for ways in which their tactics may change, their strategy is not going to change.
"They are not going to suddenly pull out of Iraq."
Mr Howard said he would talk to Mr Blair tomorrow night about Iraq, climate change, and the Ashes cricket series, "After, I hope, my eleven has defeated his", he said, referring to the Prime Minister's XI Australian team that plays the first match of the Ashes tour against the English side in Canberra tomorrow.