EDITORIAL: Will Joe Biden repeat Barack Obama’s mistake?

More than 11 years ago, Barack Obama drew his “red line” in the sand. Will the Biden administration make the same mistake?

It was August 2012 when Mr. Obama, running for a second term in the Oval Office, held a news conference and fielded a question about the ongoing civil war in Syria. The president said that he had so far avoided U.S. military intervention but that his calculations would change if Syria crossed a “red line” and used chemical weapons.

A year later, a chemical weapons attack believed to have been carried out by the regime of Bashar al-Assad killed 1,400 people near Damascus. Mr. Obama did little about his “red line” but eventually cut a deal with Vladimir Putin and Russia to have Syria turn over its chemical stockpiles to international inspectors. The agreement was a failure, the victim — as The Atlantic later put it — “of Syrian deception, Russian duplicity and American dithering.”

Fast forward to this month in the wake of the horrific Hamas terror attack on Israel. As the Jewish state prepares for a ground invasion of Gaza, militant groups threaten to escalate the conflict and have even targeted American forces. There’s little doubt that Iran is helping to fund and organize such aggression.

In recent days, Iranian-backed groups in the region, The Wall Street Journal reported this week, “launched 10 drone and rocket attacks against bases that U.S. troops use in Iraq and three on a U.S. base in southeast Syria.”

In response, the United States has ramped up the rhetoric. “My warning to the Ayatollah,” President Joe Biden said, “was that if they continue to move against” U.S. troops in the Middle East, “we will respond. And he should be prepared.”

Secretary of State Antony Blinken sent a similar message.

“The United States does not seek conflict with Iran; we do not want this war to widen,” he said Tuesday. “But if Iran or its proxies attack U.S. personnel anywhere, make no mistake, we will defend our people, we will defend our security, swiftly and decisively.”

These warnings are entirely appropriate as an exercise in deterrence. But this administration’s fiasco in Afghanistan and the Obama administration’s “red line” still haunt American diplomacy. It’s highly likely that the resolve of the Biden White House will be tested in coming weeks and months by Iranian-backed terrorists hoping to harm Americans in the region. Is Mr. Biden prepared to follow through? Or will he speak loudly and carry a small stick?

The administration faces serious challenges on the foreign policy front. Americans of all political persuasions should hope the president is up to it.