Arab-Israeli conflict:
Jordan-Syria conflict
In 1975 Jordan and Syria attempted to put aside hostilities between them and create a new alliance. By 1978 the reapproachment was off, because King Hussein of Jordan refused to allow Syria to become a dominant partner. By 1978 Syria held that the Kingdom of Jordan was behind the "Muslim Brothers" terrorist war against Syria. See also: Black September
Egypt and Yemen
Egypt fought a civil war in Yemen from 1962 to 1967. As the war expanded into a fight with another Arab nation, Saudi Arabia, Egypt withdrew its troops.
Yemen-Oman war
The Arab nation of South Yemen warred against the regime of the small Gulf state of Oman. South Yemen supported Oman's native rebellion in Dhofar. The government of Oman was aided by Iran. Eventually the Saudi-Arabian government offered money to South Yemen to withdraw their support. The rebellion then ended by 1976.
Libya-Chad conflict
In 1973 Libya effectively went to war against Chad and annexed Chadian land. Libya has a full scale invasion of Chad in 1980.
Libya-Egypt conflict
From 1973 onward, Libya was openly hostile to Egypt, and supported assassination attempts and anti-Egyptian government plots inside Egypt. Libya moved to near open warfare by 1977.
Libya-Sudan conflict
Relations between Libya and Sudan began to deteriorate after 1972. Sudan charged that Libya was involved in a terrorist plot against its government in 1976. This led to a serverence of relations between the groups. Relations were finally resumed by 1978.
Morocco and Mauritania invasion of Western Sahara
This is not part of the Middle East, though Morocco is an Arab state. Western Sahara, formerly a Spanish colonial state, was forcibly partitioned and annexed by Morocco. Algeria then aided the Polisario, Saharan rebels, to create an independent Saharan republic in 1975. Morocco and Algeria had some armed clashes for a number of years afterwards.
United States and United Kingdom invade Iraq
2003 invasion of Iraq