In Washington, the State Department urged leaders of both countries to avoid a war of words. “We would like to see both sides cool it and get back to a place where they can have a productive relationship,” the spokeswoman, Victoria Nuland, told reporters. Activists with the Free Gaza Movement, who have organized a series of flotillas to challenge Israel’s blockade of the Palestinian coastal strip, said they had no announcement about any efforts to come but that the most recent, which was stopped by Greece and Cyprus in June, would not be the last.

But Israeli diplomats and experts here and abroad said that while they were not overly concerned about a flotilla to Gaza materializing soon, the naval threat regarding the gas fields could prove more dangerous.

“Israel and Cyprus reached agreement dividing the water between the two of them for gas drilling,” Alon Liel, a former ambassador to Turkey said. “Turkey said the division was illegal. Israel is also clashing with Lebanon on demarcation and drilling rights. Turkey will also support Lebanon and things could escalate.”

Mr. Liel said that Israel hoped to export its gas via Cyprus in a few years, and that would require the digging of a large port there — something that he imagined that Turkey would try to prevent. That could mean possible clashes between Israel and Turkey like those Turkey has had with Greece over drilling and demarcation.

Israel’s foreign minister, Avigdor Lieberman, has ordered studies on how to defend Israelis from being prosecuted by the Turks over the flotilla attack last year — including urging Israelis associated with the military to avoid flying there — and get back at Turkey for its growing anti-Israel stand. Officials who spoke of the studies said they were still in the realm of brainstorming and were far from being accepted as policy. They included getting closer to Armenia, Turkey’s historic rival, and the minority Kurds in eastern Turkey, who along with Kurds in neighboring countries hope for an independent state.