My fellow Americans: If you see something, say something—even if it means CAIR will threaten to sue you.

Multiple federal agencies and the Department of Defense are on high alert for a possible Islamic terrorist attack on U.S. soil this Independence Day weekend. They've increased security at military bases and sent bulletins to law enforcement officials across the country.

The heightened stance comes in the wake of a bloodthirsty ISIS call to arms for Ramadan; multiple jihad outbreaks in Kuwait, France and Tunisia; and the arrest of at least 30 terror plotters in our country radicalized by ISIS over the past year.

"Those who seek to harm this nation and our friends take no holiday," Defense Secretary Ashton Carter warned at a Pentagon press briefing Wednesday with Joint Chiefs Chairman Gen. Martin Dempsey.

"We continue to encourage all Americans to attend public events and celebrate this country during this summer season, but always remain vigilant," DHS Secretary Jeh Johnson implored.

"We all have to be vigilant," former NYPD Detective Sgt. Wally Zeins urged.

"Remain vigilant," House Committee on Homeland Security Chairman Michael McCaul cautioned.

Unfortunately, too much of the nation remains in permanent post-9/11 snooze-button mode. Compounding this collective apathy is political correctness run amok. It's the ever-present handmaiden of terrorism: reluctance to risk offending, unwillingness to stick out one's neck, and feckless aversion of the eyes in the face of existential threats.

The Council on American-Islamic Relations, which was designated by the Justice Department as an unindicted terror co-conspirator in 2007 in the federal prosecution of the Holy Land Foundation and others for providing support to Hamas, has gleefully exploited this cultural weakness—filing intimidation and obstructionist lawsuits left and right against those who have dared to look out and speak up.

CAIR subjected a private citizen, Zaba Davis, to harassing and invasive subpoenas over her opposition to a planned construction project by the Muslim Community Association and Michigan Islamic Academy. A federal judge called CAIR's anti-free speech witch-hunt "chilling." The group has refused to pay sanctions ordered by the court.

In Cleveland, the organization has targeted a police officer for his personal views about sharia and jihad posted on his private Twitter account.

In Washington, CAIR has waged a three-year court battle to prevent Immigration and Customs Enforcement agents from pursuing basic investigative questions about border-crossers' ties to jihadist "martyrs" and radical mosques.

You'll recall that it was CAIR that advised six publicity-seeking imams who filed a federal discrimination lawsuit against U.S. Airways and the Metropolitan Airports Commission in Minneapolis-St. Paul several years ago. The Muslim clerics were removed from their flight and questioned for several hours after their suspicious behavior alarmed both passengers and crewmembers. CAIR and the instigating imams targeted "John Does"—innocent bystanders who alerted the authorities about their security concerns.

After a national backlash and passage of a congressional amendment protecting heroic John Does from frivolous p.c. lawsuits, CAIR quietly dropped its complaint. But their incessant cries of "Islamophobia" remain a potent deterrent to alert whistleblowers and witnesses who risk the manufactured wrath of jihad apologists, funders, enablers and front groups.

The litigious social justice activists have transformed common-sense vigilance into a prosecutable crime of paranoia or prejudice. CAIR and its ilk have succeeded in turning a large portion of America into security eunuchs who pay lip-service courage in times of crisis, yet recoil from the bold, unapologetic acts of self-protection that make such heroism possible in the first place.

Let's not let them win.

This weekend, remember the passengers of United Airlines Flight 93 who refused to sit back on 9/11 and let themselves be murdered in the name of Islam without a fight.

Remember the passengers and crewmembers who tackled al-Qaida shoe-bomber Richard Reid on American Airlines Flight 63 before he had a chance to blow up the plane over the Atlantic Ocean.

Remember Brian Morgenstern, the teenage Circuit City worker who fearlessly contacted authorities when suspicious Middle Easterners brought in tapes of themselves shooting off guns and shouting "Allahu Akbar." The men were convicted of plotting to kill American soldiers at Fort Dix.

And as you party, parade and celebrate on this high-alert holiday weekend, remember the words of one of the brilliant men who secured America's independence, Patrick Henry: "The battle, sir, is not to the strong alone; it is to the vigilant, the active, the brave."

Vigilance is patriotic. Grievance grifters be damned.

Michelle Malkin [email her] is the author of Invasion: How America Still Welcomes Terrorists, Criminals, and Other Foreign Menaces to Our Shores. Click here for Peter Brimelow’s review. Click here for Michelle Malkin's website. Michelle Malkin is also author of Unhinged: Exposing Liberals Gone Wild and Culture of Corruption: Obama and his Team of Tax Cheats, Crooks & Cronies.

Her latest book is  "Who Built That: Awe-Inspiring Stories of American Tinkerpreneurs."