Deputy Foreign Minister Ze'ev Elkin warned Friday that a failure by the international community to act against Syria for using chemical weapons would show Iran that the US does not act when its "red lines" are crossed.Elkin was speaking in an Army Radio interview a day after US Secretary of Defense Chuck Hagel said that the US intelligence community believes that some chemical weapons, likely sarin gas, have been used in the Syrian civil war. Hagel's announcement came after Israel's top military intelligence analyst said Tuesday that the regime of Syrian President Bashar Assad had already used chemical weapons in its fight against the country's opposition. US President Barack Obama has said that the use of chemical weapons by the Assad regime would constitute a red line that would precipitate US military intervention in Syria. However, the White House was cautious on Thursday, stating that intelligence assessments were not sufficient and "credible and corroborated facts that provide us with some degree of certainty will guide our decision-making.” Elkin posited on Friday that Washington and the international community's response to evidence of chemical weapons use in Syria will affect efforts to stop Iran's drive for a nuclear weapon."The world must take control of Assad's chemical weapons supply...the moment the international community sees that they indeed crossed a red line and used chemical weapons, they must understand that their is no choice but to take this action," Elkin told Army Radio."The Iranians are watching this. There is a question here - When they set a red line, do they act when it is crossed," he added."If they do not act after the red line they set was crossed, the Iranians will understand that red lines set by the West are very flexible and they will continue to develop their nuclear program," Elkin warned."If until now they tried to ignore our warnings and they thought that Assad had control of the weapons, now they see that the red line has likely been crossed," he stated.Elkin reiterated Israel's concerns that Assad's chemical weapons could fall into the hands of terrorist entities such as Hezbollah."What worries Israel is not who will control Syria, but rather, who will control the chemical weapons stockpile and how we eliminate the possibility of the arms being used all together," he said. "The world is beginning to understand that these chemical weapons are a danger to all."