The discovery of large natural gas reserves under the waters of the eastern Mediterranean could potentially mean a huge economic windfall for Israel and Lebanon, both resource-poor nations — if it doesn't spark new war between them.

The Hezbollah militant group has blared warnings that Israel plans to steal natural gas from Lebanese territory and vows to defend the resources with its arsenal of rockets. Israel says the fields it is developing do not extend into Lebanese waters, a claim experts say appears to be correct, but the maritime boundary between the two countries — still officially at war — has never been precisely set.

"Lebanon's need for the resistance has doubled today in light of Israeli threats to steal Lebanon's oil wealth," Hezbollah's Executive Council chief Hashem Safieddine said last month. The need to protect the offshore wealth "pushes us in the future to strengthen the resistance's capabilities."

The rumblings are worrisome because Israel and Hezbollah each accuse the other of intending to spark a new conflict following their devastating 2006 war. That fighting, in which Hezbollah's capture of two Israeli soldiers in a cross-border raid sparked a massive Israeli bombardment, killed about 1,200 Lebanese and 160 Israelis.

Since then, there has been a rare interval of peace. Hezbollah, a close ally of Syria and Iran, has not fired a rocket into Israel since. Israeli officials, however, say they believe Hezbollah has managed to triple its prewar arms stockpile to more than 40,000 rockets.