Editing War (section)

====Malthusian====

[[Malthusian catastrophe|Malthusian theories]] see expanding population and scarce resources as a source of violent conflict. [[Pope Urban II]] in 1095, on the eve of the [[First Crusade]], advocating Crusade as a solution to European overpopulation, said:
{{quote|For this land which you now inhabit, shut in on all sides by the sea and the mountain peaks, is too narrow for your large population; it scarcely furnishes food enough for its cultivators. Hence it is that you murder and devour one another, that you wage wars, and that many among you perish in civil strife. Let hatred, therefore, depart from among you; let your quarrels end. Enter upon the road to the Holy Sepulchre; wrest that land from a wicked race, and subject it to yourselves.<ref>{{cite book |title=Lend me your ears: great speeches in history |first=William |last=Safire |publisher=[[W. W. Norton & Company]] |year=2004 |isbn=978-0-393-05931-1 |page=94}}</ref>}}

This is one of the earliest expressions of what has come to be called the Malthusian theory of war, in which wars are caused by expanding populations and limited resources. [[Thomas Malthus]] (1766–1834) wrote that populations always increase until they are limited by war, disease, or [[famine]].<ref>{{cite book |title=Geography: an integrated approach |first=David |last=Waugh |publisher=[[Nelson Thornes]] |year=2000 |isbn=978-0-17-444706-1 |page=378}}</ref> The violent [[herder–farmer conflicts in Nigeria]], [[Mali]], [[Sudanese nomadic conflicts|Sudan]] and other countries in the [[Sahel]] region have been exacerbated by [[land degradation]] and population growth.<ref>{{cite news |title=In Mali, waning fortunes of Fulani herders play into Islamist hands |url=https://www.reuters.com/article/us-mali-fulani/in-mali-waning-fortunes-of-fulani-herders-play-into-islamist-hands-idUSKBN13F0L2 |work=Reuters |date=20 November 2016 |access-date=31 March 2019 |archive-date=30 March 2019 |archive-url=https://web.archive.org/web/20190330131908/https://www.reuters.com/article/us-mali-fulani/in-mali-waning-fortunes-of-fulani-herders-play-into-islamist-hands-idUSKBN13F0L2 |url-status=live }}</ref><ref>{{cite news |title=How Climate Change Is Spurring Land Conflict in Nigeria |url=https://time.com/5324712/climate-change-nigeria/ |magazine=Time |date=28 June 2018 |access-date=31 March 2019 |archive-date=4 March 2021 |archive-url=https://web.archive.org/web/20210304231237/https://time.com/5324712/climate-change-nigeria/ |url-status=live }}</ref><ref>{{cite news |title=The Deadliest Conflict You've Never Heard of |url=https://www.foreignaffairs.com/articles/nigeria/2019-01-23/deadliest-conflict-youve-never-heard |work=[[Foreign Policy]] |date=23 January 2019 |access-date=31 March 2019 |archive-date=18 February 2019 |archive-url=https://web.archive.org/web/20190218125507/https://www.foreignaffairs.com/articles/nigeria/2019-01-23/deadliest-conflict-youve-never-heard |url-status=live }}</ref>