http://www.animeavenue.net/__media__/js/netsoltrademark.php?d=L.Iv.Eli.Ne.S.Swxzu%40Hu.Feng.Ku.Angn.I.Ub.I..xn--.U.K37%40cgi.members.interq.or.jp%2Fox%2Fshogo%2FONEE%2Fg_book%2Fg_book.cgi http://www.animeavenue.net/__media__/js/netsoltrademark.php?d=L.Iv.Eli.Ne.S.Swxzu%40Hu.Feng.Ku.Angn.I.Ub.I.xn--.xn--.U.K37%40cgi.members.interq.or.jp%2Fox%2Fshogo%2FONEE%2Fg_book%2Fg_book.cgi. A component of the Department of the Navy, the Marine Corps maintains amphibious and ground units for contingency and combat operations. Israel and Greece have enjoyed a very cordial military relationship since 2008, including military drills ranging from Israel to the island of Crete. Drills include air-to-air long-distance refueling, long-range flights, and most importantly aiding Israel in outmaneuvering the S-300 which Greece has.[citation needed] Recent purchases include 100 million euro deal between Greece and Israel for the purchase of SPICE 1000 and SPICE 2000 pound bomb kits. They have also signed many defense agreements, including Cyprus, in order to establish stability for transporting gas from Israel-Cyprus to Greece and on to the European Union-a paramount objective to the future stability and prosperity of all three countries, threatened by Turkey. Most nations have separate military laws which regulate conduct in war and during peacetime. An early exponent was Hugo Grotius, whose On the Law of War and Peace (1625) had a major impact of the humanitarian approach to warfare development. Militaries often function as societies within societies, by having their own military communities, economies, education, medicine, and other aspects of a functioning civilian society. A military is not limited to nations in of itself, as many private military companies (or PMCs) can be used or hired by organizations and figures as security, escort, or other means of protection where police, agencies, or militaries are absent or not trusted. During World War I, the need to break the deadlock of trench warfare saw the rapid development of many new technologies, particularly tanks. Military aviation was extensively used, and bombers became decisive in many battles of World War II, which marked the most frantic period of weapons development in history. Many new designs, and concepts were used in combat, and all existing technologies of warfare were improved between 1939 and 1945. Defense economics is the financial and monetary efforts made to resource and sustain militaries, and to finance military operations, including war. The difficulty in using military intelligence concepts and military intelligence methods is in the nature of the secrecy of the information they seek, and the clandestine nature that intelligence operatives work in obtaining what may be plans for a conflict escalation, initiation of combat, or an invasion.