Seek Martyrdom?

You may have heard in the past week or so that the "#2 leader" of Al-Qaeda, Ayman al-Zawahri, called on Muslims "to rise up and seek martyrdom and attack and inflict harm on crusaders." Any doubts as to whether or not the war on terror is a holy war should be placed to rest by this quote from al-Zawahri:

"The war with Israel does not depend on cease-fires ... . It is a jihad (holy war) for the sake of God and will last until (our) religion prevails ... from Spain to Iraq. We will attack everywhere."

Towards the end of this article in the Houston Chronicle, al-Zawahri urged his fellow Muslims once more, saying, "Rely on God and fight your enemies ... make yourselves martyrs."

But as I look at Merriam-Webster's definitions for "martyr," I find the following:

1 : a person who voluntarily suffers death as the penalty of witnessing to and refusing to renounce a religion
2 : a person who sacrifices something of great value and especially life itself for the sake of principle

So that brings questions - What "religion" is al-Zawahri witnessing to? What "principle" is he seeking to sacrifice himself (& others) for? I guess I always assumed that martyrdom was not something that was to be sought, but something that happened. Would the apostle Paul have been considered a martyr if he had killed himself? He would have been voluntarily suffering death, and he repeatedly witnessed to and refused to renounce the gospel of Jesus Christ.