The Wall Street Journal, December 14 2017 – As the U.S. military campaign against ISIS winds down in the Middle East, the Trump administration is turning its focus to what it sees as a bigger threat: Iran, The Wall Street Journal reported on Thursday.

U.S. officials are wrestling with where and how to repel what they describe as a significant Iranian military expansion across the region, a development of increasing concern in Washington, Tel Aviv and Riyadh.

“Our leadership has set as an objective not to allow Iran and its proxies to be able to establish a presence in Syria that they can use to threaten our allies or us in the region,” one senior U.S. administration official said. “There are different ways to implement that, and we are still working through them.”

President Donald Trump’s national security adviser, Lt. Gen. H.R. McMaster, is considering giving a policy speech on Syria early next year that would outline the new administration strategy, according to people familiar with his thinking.

One major issue the Trump administration has to address is whether to make confronting Iran an explicit new goal for the more than 2,000 American forces currently in Syria.

Defense Secretary Jim Mattis has said troops will remain in the country for the foreseeable future to ensure that ISIS doesn’t regain a foothold or its remnants don’t morph into a dangerous new threat.

But those troops could also be placed at the forefront of a new effort to prevent Iran from cementing its military presence in Syria or establishing a secure route across the country that would allow Tehran to easily ferry advanced weapons to allies on Israel’s border, according to U.S. officials and others familiar with the continuing discussions.

“The military presence in Syria increasingly should be the center of gravity for an Iranian neutralization strategy,” said Mark Dubowitz, CEO of the Foundation for Defense of Democracies, a Washington think tank with close ties to the Trump administration. “There’s no political leverage without American military power on the ground.”

Iran has castigated the U.S. for its Mideast presence, saying Washington is backing terrorists fighting against the Syrian regime. Iran didn’t respond to a request for comment on the U.S. shift.

While Mr. Trump sketched out a broad plan in October for combating Iran’s influence, the U.S. military has been focused on eliminating ISIS strongholds in Syria and Iraq. That project, U.S. officials concede, has allowed Iran to increase its influence, especially in Syria. Administration officials estimate that Tehran and its allies now provide 80% of the fighters for President Bashar al-Assad’s depleted regime there. By some estimates, there are 125,000 Iranian forces currently in Syria.

Turning the focus from ISIS to Iran would come with a litany of challenges, including concerns about triggering a deadly backlash from Iran targeting American forces in the region.

That prospect is a paramount concern to U.S. military officials, especially those who fought in Iraq a decade ago and remember the deadly effect Iranian-supplied explosives had on U.S. forces in the country.

To hammer home that disquiet, Central Intelligence Agency chief Mike Pompeo sent a private warning last month to Gen. Qassem Soleimani, the head of Iran’s elite expeditionary Quds Force. In the letter, Mr. Pompeo said recently, the U.S. warned Gen. Soleimani that the administration “will hold he and Iran accountable for any attacks on American interests in Iraq by forces that are under their control.”

Iran’s state-media revealed the existence of the letter and said a CIA operative tried to hand-deliver it to Gen. Soleimani while he was visiting the embattled Syrian town of Abu Kamal, close to the border with Iraq. Mr. Soleimani refused to open the letter, according to Mr. Pompeo and Iranian media.

The Trump administration has already shown its willingness to directly confront Iran in Syria. Over the summer, the U.S. military shot down two armed Iranian drones flying near American forces operating in southern Syria. Though tensions quickly cooled afterward, the incidents showed how serious confrontations in Syria could become.

Gen. McMaster has made it clear in recent days that the U.S. is crafting ways to contain that threat in Syria.

“What we face is the prospect of Iran having a proxy army on the borders of Israel,” he said at a public forum earlier this month.

American and Israeli officials are especially troubled about intelligence suggesting that Iran is establishing a military facility in northwestern Syria to make long-range missiles. Israel has carried out more than 100 airstrikes in Syria, most of them aimed at what it says are convoys ferrying weapons to Hezbollah fighters.

After the most recent airstrike on an Iranian military base near Damascus in early December, Israeli Prime Minister Benjamin Netanyahu said his country would “not allow a regime hellbent on the annihilation of the Jewish state…to entrench itself militarily in Syria.”

The Trump administration is seeking ways to prevent the Syrian war from transforming into a new regional conflict between Israel and Iran. The U.S. and its allies are trying to use the expansion of de-escalation zones in Syria to halt Iran’s expansion along the borders with Israel and Jordan. But critics say the agreements have actually shored up Iran’s gains and undercut the goals.