Five weeks ago, the head of the Arab League capped a summit in Qatar with an impassioned appeal to strengthen the rebel fighters trying to bring down Syrian President Bashar Assad. On Sunday, he denounced Israeli’s airstrike into Assad’s territory as a dangerous threat to regional stability.

The contrast reflects a fundamental conundrum for Arab leaders.

Nearly all Arab states have sided with the rebel forces seeking to topple Assad and inflict a blow to his main ally, Iran. And Sunday’s attack by Israeli warplanes in Syria — the second in three days — was the type of punishing response many Arab leaders have urged from the West against Assad after more than two years of civil war.

The fact the fighter jets came from Israel, however, exposes the complications and regional crosscurrents that make Syria the Arab Spring’s most intricate puzzle.

While Israel and much of the Arab world share suspicions about Iran, including worries about its nuclear ambitions and expanding military, the perception that they are allied against Assad — even indirectly — is strongly knocked down by many Arab leaders.

The airstrikes also highlight one of the critical side issues of the Syrian conflict: the Iranian-backed Shiite militant group Hezbollah in Lebanon.

The Israeli warplanes apparently targeted a shipment of highly accurate, Iranian-made Fateh-110 guided missiles believed to be bound for Hezbollah.

Toppling Assad would cut the arms pipeline that runs from Shiite giant Iran to Hezbollah. But Hezbollah remains deeply popular on the Arab street for its battles with Israel, including a war in 2006 in which Hezbollah fired thousands of rockets into Israel.

No Arab leader wants to be perceived as giving a green light for Israeli attacks.

Arab League chief Nabil Elaraby warned of serious repercussions from the Israeli attacks and called on the U.N. Security Council to “immediately move to stop the Israeli aggressions on Syria.”

Elaraby described the Israeli airstrikes as a “grave violation of the sovereignty of an Arab state that will further complicate the issue in Syria and expose the region’s security and stability to the most serious threats and consequences.”

Also Sunday, Elaraby held talks with Mouaz al-Khatib, who recently resigned as chief of the Syrian National Coalition of opposition forces, to discuss the Israeli raids and other issues. At an Arab League summit in late March, Elaraby backed a declaration by host Qatar that gave member states “the right” to back the Syrian opposition.

Qatar and other wealthy Gulf Arab have become leading backers of Syria’s opposition in a dual bid to expand their influence while crippling Iran. Official Gulf reaction to the Israeli attacks was limited to straightforward reports with little commentary.

Egyptian President Mohammed Morsi condemned Israel’s airstrikes, calling them a violation of international law and warning they complicate the civil war in that country.

The statement from Morsi’s office added that Egypt also “strongly objects” to the bloodshed and the use of Syria’s military against its people, but rejected the violation of Syrian sovereignty and “exploiting its internal crisis under whatever pretext.”

Egypt launched an Arab bid to bring a peaceful end Syria’s civil war, but it gained little momentum.

Lebanon’s Foreign Minister Adnan Mansour called on the Arab League to take a “firm stance regarding Israel’s aggression against Syria.” Mansour said that Israel is paving the way “for a wide aggression that would blow up the region.”