Q:

Was the Klingon Empire at war with the Federation during the events shown in DS9: The Way of the Warrior?

I have just watched "The Way of the Warrior" (first episode of 4th season of Deep Space Nine) and I found one of Sisko's reactions weird.
He says to Dukat:

 Then I'll be there to reason with them. I doubt the Klingons will fire on a Federation ship.

Just a few minutes (hours) after telling his own crew, in DS9's Ops, that:

 (...) The Klingons have withdrawn from the Khitomer Accords. The peace treaty between the Federation and the Klingon Empire... has ended.

The reaction to Dukat seems to be the opposite of his reaction to the crew of DS9. What prevents the Klingons from firing based on these events?
Can anyone explain this to me? Is there anything, that I'm missing? Because, for me, this is a clear mistake in a script.

A:

There's a big difference between withdrawing from a peace treaty and going to war. 
The Klingon withdrawal from the Khitomer Accords doesn't necessarily mean that they want to go to war with the Federation, which is of course what would happen if they fired on a Federation ship.
There's no peace treaty between the USA and North Korea, but it's still highly unlikely that North Korea would fire on a US ship outside North Korean territory.

