Given the question: Information:  - Air Chief Marshal Sir David George Evans GCB , CBE ( born 14 July 1924 ) is a retired senior commander of the Royal Air Force .  - The Battle of Britain (German: "die Luftschlacht um England", literally "Air battle for England") was a combat of the Second World War, when the Royal Air Force (RAF) defended the United Kingdom (UK) against the German Air Force (Luftwaffe) attacks from the end of June 1940. It is described as the first major campaign fought entirely by air forces. The British officially recognise its duration as from 10 July until 31 October 1940 that overlaps with the period of large-scale night attacks known as the Blitz, while German historians do not accept this subdivision and regard it as a campaign lasting from July 1940 to June 1941.  - The United States Armed Forces are the federal armed forces of the United States. They consist of the Army, Marine Corps, Navy, Air Force, and Coast Guard. The President of the United States is the military's overall head, and helps form military policy with the U.S. Department of Defense (DoD), a federal executive department, acting as the principal organ by which military policy is carried out. From the time of its inception, the military played a decisive role in the history of the United States. A sense of national unity and identity was forged as a result of victory in the First Barbary War and the Second Barbary War. Even so, the Founders were suspicious of a permanent military force. It played an important role in the American Civil War, where leading generals on both sides were picked from members of the United States military. Not until the outbreak of World War II did a large standing army become officially established. The National Security Act of 1947, adopted following World War II and during the Cold War's onset, created the modern U.S. military framework; the Act merged previously Cabinet-level Department of War and the Department of the Navy into the National Military Establishment (renamed the Department of Defense in 1949), headed by the Secretary of Defense; and created the Department of the Air Force and National Security Council.  - The Royal Air Force (RAF) is the United Kingdom's aerial warfare force. Formed towards the end of the First World War on 1 April 1918, it is the oldest independent air force in the world. Following victory over the Central Powers in 1918 the RAF emerged as, at the time, the largest air force in the world. Since its formation, the RAF has taken a significant role in British military history, in particular, playing a large part in the Second World War where it fought its most famous campaign, the Battle of Britain.  - Air chief marshal (Air Chf Mshl or ACM) is a four-star air officer rank which originated in and continues to be used by the Royal Air Force, where it is the most senior peacetime air force rank. The rank is also used by the air forces of many countries that have historical British influence and it is sometimes used as the English translation of an equivalent rank in countries which have a non-English air force-specific rank structure. Air chief marshal is a four-star air officer rank and has a NATO ranking code of OF-9. An air chief marshal is equivalent to an admiral in the Royal Navy or a General in the British Army or the Royal Marines. In other forces, such as the United States Armed Forces and the Canadian Armed Forces, the equivalent four-star rank is General.  - The Central Powers , consisting of Germany, , the Ottoman Empire and Bulgaria  hence also known as the Quadruple Alliance  was one of the two main factions during World War I (191418). It faced and was defeated by the Allied Powers that had formed around the Triple Entente, after which it was dissolved.    What is the relationship between 'david evans ' and 'world war ii'?
The answer is:
conflict