The long and bitter relationship between Israel's Benjamin Netanyahu and Hamas

In 1996, Israel faced a critical election for prime minister. The conservative candidate, Benjamin Netanyahu, was the underdog. The heavy favorite for prime minister was Shimon Peres, the dovish incumbent and the leading advocate for a peace agreement with the Palestinians.

As the election approached, Hamas suicide bombers carried out several deadly attacks, killing more than 50 Israelis.

Professor Nathan Brown, a Middle East expert at George Washington University, said this had a powerful impact on Israeli voters.

"Suddenly Netanyahu's message, which was, 'we can't trust the peace process,' started making an awful lot more sense," said Brown.

Those Hamas attacks boosted Netanyahu at the polls.

"In a very narrow victory, he was elected prime minister. So there was kind of a symbiotic relationship between them," Brown added.

Setting the stage for the current war

After many twists and turns over the years, this tortured relationship is now playing out in the full-scale war in Gaza.

"Obviously, there is no love lost between Netanyahu and Hamas," said Khaled Elgindy with the Middle East Institute in Washington.

They may be sworn enemies, yet they also kind of need each other. On multiple occasions, the hardline policies of one have been used to the advantage of the other.

"Hamas became useful to Netanyahu as a way to ensure that a cohesive Palestinian leadership did not emerge, and therefore there couldn't be a Palestinian state," said Elgindy.

In turn, Hamas has never negotiated with Israel and benefits from Netanyahu's recurring security crackdowns against Palestinians, said Nathan Brown.

"When the peace process looks like it's viable, Hamas is in a bind" he said, noting that at various times Palestinians believed the