Appearing on CBS' "Face the Nation" Sunday, the Arizona Republican said the attacks - the worst in Iraq in months - are indicative that improving the situation there is a slow process and a "terrible tragedy."
He blamed extremists trying to ignite sectarian violence, but said that while such attacks continue, "they are not sustainable.
"The majority of the people are opposed to them. And the Iraqi military will be able to handle this transition. But it's not going to be without tragedies such as we've seen just today," he added.
No, McCain said. "We are not operating in a vacuum now.
"The sooner the decision is made, the sooner we get people over there and are able to implement the strategy that will succeed."
He admitted that the government of President Hamid Karzai - should he win re-election in the runoff - has to be more accountable in eliminating corruption. But McCain argued that a troop increase should not wait until the political situation there is resolved.
"I think [President Obama] will make the right decision. I want to support that decision," McCain said. "I also just want to briefly add, there's a lot of other areas, now that we are moving forward, when we move forward, for the proper security environment. There's governance. There's some problems within our own civilian side as to how we are going to be partners in implementing this strategy. And a lot of other issues that need to be addressed as well. But without security, none of the other aspects of a winning strategy can succeed."
Schieffer asked if Senator McCain could support a possible move to a hybrid strategy in Afghanistan, incorporating some elements of the counterterrorism strategy Vice President Joe Biden supports and General Stanley McChrystal's counterinsurgency strategy.
"It may be a matter of semantics," McCain said. "I don't know how you make them hybrid. There are elements of counterterrorism in counterinsurgency, but fundamentally, counterinsurgency will require the implementation of the strategy that General McChrystal has recommended, in my view.
"And the counterterrorism strategy - killing people and then returning to base - has been proven to be a very disastrous strategy in Iraq and in other places."