Application Profile: The Six Day War
This article covers Stoa's current LD resolution: Preemptive warfare is morally justified.
Affirmatives everywhere are winning with a really simple narrative: "we have to defend ourselves!"
To do this, many cases assume a value like national safety, and then cut to a contention with the following application: The Six Day War Application. It goes something like this:
"We can't just sit back and do nothing. Check out Israel. Egypt was about to attack them, but Israel struck first and scared them off. Look at how great preemptive warfare is!"
Why the Application Works
The Six Day War is one of the most prominent examples of preemptive warfare in recent history. And since preemptive warfare is a rare military strategy, there just aren't that many documented examples to choose from. Meaning the ones we do have are low-hanging fruit.
The application also has a persuasive backstory. Israel is a tiny nation, surrounded by its enemies. Most judges already want to see Israel emerge victorious, so leveraging an application about it is an easy move for affirmatives to make.
How You Can Beat It
Assuming the debate isn't value-centric, the most important arguments your opponent has are his applications. You have to deal with them: applications are tangible, powerful, and persuasive.
Right now, most debaters are choosing to run the standard no-link response: "This wasn't an example of preemptive warfare. So ignore it." This response isn't bad, but usually requires a lot of historical analysis that the average negative isn't prepared to deliver. You'd need to take some time to re-explain the scenario Israel was in, and then, in detail, articulate how it wasn't preemptive.
After an affirmative spends 90 seconds delivering an application that sounds an awful lot like preemptive warfare, a 10-second "no it's not" isn't going to get the job done.
Here are two responses that will.
1. Pure Turn
While most responses are defense (you don't win this application) the pure turn is offense (I win the application). Your argument: The Six Day War is a story of tragedy, not success.
Here's a quote from Israel Prime Minister Menachem Begin in 1982:
"In June 1967, we again had a choice. The Egyptian Army concentrations in the Sinai approaches do not prove that Nasser was really about to attack us. We must be honest with ourselves. We decided to attack him." 
Plenty of historians believe that Israel falls on the wrong side of history. Some point out that Egypt's move to Israel's border was an intimidation move, and nothing more.
In either case, Israel reacted to non-violence with violence. Their choice resulted in a brutal conflict: one that claimed thousands of lives and could've been avoided.
This is another offensive response. Instead of focusing on how the example happened, the counter-application focuses on the implications of the example: and how horrifying they are.
Fifty years after Egypt moved a few of their troops to the Israeli border, North Korea is testing weapons of mass destruction and promising to wipe the United States off the face of the earth. Is the affirmative ready to follow Israel's example?
For decades, the U.S. has avoided a military conflict with North Korea. We know that it's too dangerous: a nuclear war would decimate countless lives and threaten the continuity of our species.
This goes beyond the U.S. Because so much of the modern world is connected through military alliances, attacking one nation implicates dozens more. We simply can't afford to treat intimidation with violence.
So sure. Half a century ago, Israel's preemptive strike resulted in *only* a few thousand casualties. But to apply that ideology to the globe is a choice that begs for annihilation.
 “EXCERPTS FROM BEGIN SPEECH AT NATIONAL DEFENSE COLLEGE.” The New York Times, The New York Times, 20 Aug. 1982, www.nytimes.com/1982/08/21/world/excerpts-from-begin-speech-at-national-defense-college.html.