Middle Eastern wars that have had a negative effect on Europe’s economy include conflicts set on different historical periods.
The Crusades, which occurred between the 11th century to the 13th century, were highly expensive, and so, acted as major factors in the decrease of European wealth at the time (save for Italy, where positive effects were noticed).
More recently, the Yom Kippur War, a war fought between Israel and Arab countries led by Syria and Egypt, caused the 1973 oil crisis, after the United States of America’s decision to support Israel. The OAPEC (Organization of Arab Petroleum Exporting Countries) then decided to promulgate an embargo in response. The embargo ended up raising the oil price from US$3 to US$12, deeply affecting the global economy of the time.