American Secretary of State John Kerry’s rapid response to allegations that Syria had used chemical weapons, made Tuesday by the head of the research division at Military Intelligence, attests to the U.S. administration’s concerns that Israel won’t stop at embarrassing President Barack Obama over this issue. Instead, it will continue challenging the American president’s position regarding Iran.

The U.S. administration previously stated that the use of chemical weapons by Syrian President Bashar Assad would “cross a red line” and could lead to American intervention in the Syrian civil war. Brig. Gen. Itai Brun’s public announcement − that the Syrians used lethal chemical ordnance on a number of occasions − could be perceived as a blunt Israeli challenge to the U.S. president: You declared that the U.S. would take action if Assad crossed that line, and we are presenting you with evidence that he did. What are you going to do about it?

The Obama administration clearly understands that Israel is presenting it with a challenge, and that Obama’s conduct on this issue will indicate his determination to abide by the commitment he also made to act with regard to the Iranian nuclear program. Israel could have been satisfied with simply delivering the information it had regarding Assad’s use of chemical weapons to U.S. Secretary of Defense Chuck Hagel in private discussions, but it opted to make a public declaration by a senior intelligence official.

No one in the U.S. administration believes that Brig. Gen. Brun made this declaration of his own volition. And if that were not enough, Brun − in response to a question by a former head of Military Intelligence, Amos Yadlin − added that this was a worrisome development, and met with an inadequate international response.

The message is clear. Israel is closely following U.S. activity regarding Syria after the regime there crossed a red line. If the U.S. fails to act, it will be hard for Israel to believe that it will follow through on its commitment to thwart Iran from acquiring nuclear weapons. Taking action in Syria is much simpler and less dangerous than preventing Iran from going nuclear.

Brun’s declaration exposed the U.S.-Israel disagreement over Syria’s chemical arsenal, and the Israeli decision to try to accelerate the Americans’ decision on Iran. Sarin, the poisonous-nerve gas allegedly used by the Syrian army against rebels, is only the tip of the iceberg.

The crux of the matter is the enriched uranium in Iran. The clock is ticking, Israel is signaling to the U.S., and we won’t be able to rely on you when it comes to this existential issue affecting us. If we see that you are unwilling to take action even in Syria, we may have no option other than to take action in Iran on our own.

This position was bluntly stated by Yadlin at the same event where Brun made his declaration. Yadlin said that, for all intents and purposes, Iran has already crossed the red line drawn by Prime Minister Benjamin Netanyahu in his speech last September at the United Nations. Yadlin also directed sarcastic remarks at the international community, including the U.S., saying that what seems to be of more interest to them is to stop Israel from attacking, rather than stopping Iran from going nuclear.

Even though Yadlin is an officer in the reserves and not an official Israeli representative, his words will reverberate in Washington as another public Israeli challenge to Obama − especially as the Prime Minister’s Office has not expressed any reservations about the remarks.

Secretary of State Kerry rushed to clarify that he spoke with Netanyahu, who “could not confirm the statements made by Israel’s Intelligence officer.” However, this officer has let the genie out of the bottle, transforming the confrontation between Israel and the U.S. over Iran from a behind-the-scenes discussion into a public dispute.