The country has become "a textbook example of foreign interference today in local conflicts," Ghassan Salame told the New York-based International Peace Institute on Wednesday.
"[Between] six and 10 countries are permanently interfering in Libya's problem," funnelling arms, cash and military advice to the country, Salame warned.
"I always considered my compatriots in Lebanon as stupid enough to commit suicide with somebody else's money. The Libyans are even worse. They are committing suicide with their money."
Lebanon was torn apart by a brutal civil war between 1975 and 1990, which observers say was exacerbated by foreign intervention.
Salame stressed that Libya was a rich country that "can pay for its own suicide".
He again urged the international community to "not only contain this conflict".
"We need to work in order to put an end to this conflict," Salame said, regretting the lack of unity at the UN over the issue.
He was speaking a day after warning the UN Security Council that the ongoing battle for Tripoli launched by renegade military commander Khalifa Haftar on April 4 was "just the start of a long and bloody war".
More than 75,000 people have been driven from their homes in the latest fighting and 510 have been killed, according to the World Health Organization (WHO).
More than 2,400 people have also been wounded, while 100,000 people are feared trapped by the clashes raging on the outskirts of Tripoli.
The war has pitted Haftar's forces against those of the UN-recognised government based in Tripoli.
The Security Council failed last month to agree on a draft resolution demanding a ceasefire in Libya and a return to political talks to end the conflict.