U.S. law enforcement on guard for potential Iranian retaliation after Soleimani's killing

Security is tightening in New York, Washington, D.C. and San Francisco in the aftermath of the U.S. killing Qasem Soleimani, one of Iran's most powerful figures.

The big picture: Iran largely stopped targeting the West after the Iran deal, but hacking re-emerged against the U.S. as tensions escalated, with activity that appears to be more for information gathering purposes than to cause harm. This could be the regime's tool of choice for retaliating against the U.S., according to multiple reports.

What's happening:

• New York Mayor Bill de Blasio said he ordered the deployment of the National Guard to city airports on Friday and called for "increased security at critical infrastructure points across the state." He noted the state has not received any direct threats.
• The United States Park Police announced plans on Friday to step up patrols at landmarks in New York, Washington, D.C. and San Francisco, AP reports. The Statue of Liberty, the Washington Monument and the Lincoln and Jefferson memorials are among icons the park police are responsible for protecting.
• The LAPD said Friday it is "monitoring the events developing in Iran" and in communication "with state, local, federal and international law enforcement," although "there is no credible threat to Los Angeles."
• The Arlington National Cemetery, a military cemetery for U.S. service members, said Friday it is implementing ID checks at all entrances.
• Chicago's police force put out a Friday statement indicating it will continue standard patrols with Homeland Security to monitor "critical infrastructure."

Go deeper:

• Why Qasem Soleimani mattered
• How Trump decided to kill Iran's Soleimani