When the United States was attacked by terrorists on September 11th , many wondered who would pay for our catastrophic losses. This was something that we had never experienced before. There was no right way to react. We had been attacked by an evil that was not tied to a specific "state". There was no one country that we could punish in order to avenge what happened on that day. However, we have since attacked two different countries, both having a history with aiding Al Qaeda, making them an enemy as well in the "war against terrorism.".
When looking at this situation, it is tough to compare it to the principles of jus ad bellum. Jus ad bellum has 4 main principles which state just reasons for going to war. The first of these is to punish evil. In the case of the "war against terrorism", where the United States invaded Afghanistan and Iraq, we were attacking in order to punish evil. Saddam Hussein was (is) an evil leader. We may not have gone into the war with Iraq with the intention of taking over their government, however, in the end, we did destroy an evil. Looking at it from this perspective does, in fact, follow one of the principles of jus ad bellum.
The other principle that supports that the "war against terrorism" has to do with proportionality, or the idea that the outcome will be successful. Our original goal was to take Saddam out of power in Iraq by any means necessary. Many say that the United States is too cocky, thinking we are the world's superpower. However, it is hard to argue against this idea. Our military is the most powerful in the world. There was no real reason to fear defeat when invading Iraq. .
The final two just causes for going to war do not apply to the "war against terrorism". These two causes have to do with righting a wrong (self-defense) and going to war as a last resort. However, in order to be considered "just cause", only one principle must apply. .
When President Bush declared war against terrorism, he was not simply talking about Al Qaeda.