The images are haunting: men in gas masks firing rapidly through dark vapors, people contorted by pain from within. It is widely accepted that chemical warfare is a form of modern warfare and World War I is credited with introducing this type of combat. Recent archaeological discoveries show that this may not be the case. According to the Merriam-Webster dictionary, chemical warfare is “tactical warfare using incendiary mixtures, irritating, burning, toxic, or asphyxiating fumes or gases.” (Chemical Warfare, 2011) It's a tempting and attractive way to dispose of enemies without drawing a sword or raising a gun. Chemical weapons agents, or CWA as they are more commonly known, are classified into five main groups: riot control agents, nerve agents, blister agents, blood agents, and choking agents. Each is devastating to those in their path, and for decades scientists have worked to create more manageable and deadlier types. Today, eight countries are known to possess chemical weapons (OPCW), but, according to new archaeological discoveries, this may not only be a source of widespread concern in the modern world. Contrary to popular belief that it was the Germans who introduced chemical weapons. In modern warfare during World War I, the use of chemical weapons has existed since ancient times. Historians consider the use of poison on arrowheads to be the beginning of humanity's foray into this type of tactical warfare. (WIFA. 2005) Toxic substances became the predominant form of chemical warfare in the ancient world, and it was common for attacking armies to poison the water supplies of besieged cities or use other poisonous methods to silently eliminate their enemies . Look for examples of poison...... middle of paper ......(2005). Chemical weapons. Achieving Critical Will, retrieved from http://www.reachingcriticalwill.org/legal/cw/cwindex.htmlArnold, J. (2005). Chemical warfare. emedicinehealth, retrieved from http://www.emedicinehealth.com/chemical_warfare/article_em.htmOPCW. (nd). About chemical weapons. Retrieved from http://www.opcw.org/about-chemicalweapons/what-is-a-chemical-weaponMayor, A. (2009). Greek fire, poisoned arrows and scorpion bombs: biological and chemical warfare in the ancient world. (2 ed., pp. 1-14). New York, NY: Overlook Press. Retrieved from http://www.stanford.edu/dept/HPS/GreekFire.pdfCDC. (2006). Phosgene Facts. Centers for Desease Control and Prevention, retrieved from http://www.bt.cdc.gov/agent/phosgene/basics/facts.aspGoebel, G. (July 1, 2010). A story of chemical warfare. Retrieved from http://www.vectorsite.net/twgas_1.html