Lebanon and Syria have not been in direct conflict since the Syrian army ended the Syrian Occupation of Lebanon in April 2005. There have been some border skirmishes, especially because some of the Syrian Civil War spills over into Lebanon, but there is no declared war between the Syrian Regime or any of the other Syrian Civil War parties and Lebanon.
It is being fought all over Syria, with occassional incidents across the borders in Lebanon and Turkey.
Syria lost territory to Israel in the 1967 War (the Golan Heights). It made no successful incursions into Israel from that point onwards. The Syrian Army did invade Lebanon in 1982 and occupied Lebanon until 2006.
After World War I, the French received a colonial mandate over Greater Syria, which became the countries of Syria and Lebanon.
All three have had civil wars in recent times: Syria: 2011-Present - Syrian Civil War OR Syrian Arab Spring War Lebanon: 1975-1991 - Lebanese Civil War Jordan: 1970-1971 - Black September OR Jordanian Civil War
Syria is involved in a civil war now, 2014
In 1923, as part of the outcome of World War I, France was awarded with the "Mandate of Syria" by the League of Nations. This mandate empowered France to administer and otherwise control affairs in this area of the Middle East, which in fact consisted of portions of both modern-day Syria and Lebanon.
Israel was on one side, and Egypt, Syria, Lebanon, and Jordan were on the other.
1967. Israel fought the war to secure land from Syria, Jordan, Lebanon, and Egypt.
1948-Israeli War of Independence/al-Naqba (Arabic for "The Disaster")=Egypt, Jordan, Syria, Lebanon, Iraq attacked Israel along with many from the Palestinian population 1967-Six Day War-Egypt, Syria, Jordan 1968-Egypt's War of Attrition 1973 Yom Kippur War/Surprise attack by Egypt/Syria. 1982-First Lebanon War 2006 Lebanon War 2008 Gaza War
Lebanon is not a world power, it is at most a regional power, and it is one of the less powerful nations in the middle east. It has usually been dominated by Syria, although the current civil war in Syria could change that.
The actual conflict in Syria can lead to a regional war by spreading throughout its border to Turkey, Iraq, Lebanon, and if Iran gets attacked, then there could be a World War 3.
Turkey along with Iraq, Jordan, Lebanon, Palestine (now Israel), Syria, Yemen became independent states after the collapse of the Ottoman Empire.