Last month, five members of Congress wrote to the State Department inspector general and similar officials at other federal agencies, declaring that U.S. policies and activities "appear to be the result of influence operations conducted by individuals and organizations associated with the Muslim Brotherhood," Egypt's oldest and largest Islamic organization. The members asked for a report on the purported influence operations and for recommendations for "corrective action."

As a former official at the National Security Council and the State Department, I can attest to the critical importance of sustaining the integrity of our national-security institutions. The question is not whether we face threats, but rather how we make Americans safer while ensuring our values.

As reflected in an Aug. 2 commentary (" We must not go easy on radical Islam ") by one of the authors of the congressional letter, Rep. Michele Bachmann, R-Minn., views vary widely about the Muslim Brotherhood -- and about the possibility for constructive engagement between U.S. officials and Egyptian President Mohammed Morsi, a leader in the movement. And while a new administration -- whether led by Mitt Romney or Barack Obama -- is likely to engage politicians in Egypt connected to the Brotherhood (as the Bush administration sought to do after the 2005 elections in Egypt), debates on this question will continue.

So why did the congressional letter to the State Department evoke such a storm of protest -- most prominently from Sen. John McCain , R-Ariz., but from so many others as well? In fact, the outrage was not inspired by the views, however controversial, of the five members of Congress on policy toward the Islamic world. Rather, it was the letter's use of innuendo -- in particular, against Huma Abedin , the State Department's deputy chief of staff and a longtime aide to Secretary of State Hillary Clinton.

Citing a report from a Washington think tank run by a former Reagan administration staffer, the letter states that Ms. Abedin has family members "connected to Muslim Brotherhood operatives and/or organizations." It makes note of her access to the secretary of state and asks the inspector general to identify whether any U.S. citizens may be agents of the Muslim Brotherhood.

Pressed by reporters, former presidential candidate Newt Gingrich defended the inquiry , arguing that "there weren't allegations, there was a question."

Full disclosure: I've worked with Huma Abedin . And like Sen. McCain, who condemned the congressional letter, I know her as a patriotic, honorable, dedicated and hardworking public servant.

But as stellar as they are, Abedin's qualities are not the issue. The issue is the poison of public innuendo. Innuendo is not the wild claim, the allegation of wrongdoing, which can be easily discredited. Rather, it is the remark, the hint -- or, to use Gingrich's term, the "question" -- that creates the suggestion of guilt without any accusation of wrongdoing.

Does the letter fit that definition?

Abedin is the only State Department official other than the secretary mentioned in the letter, which asserts the Muslim Brotherhood is engaged in information operations. It alleges that Abedin has potentially nefarious connections and asks about Muslim Brotherhood agents in the U.S. government.

That's innuendo. It's damning, and unless subjected to the disdain it deserves, it imposes upon its target the impossible task of proving his or her innocence when he or she has not been accused of any wrongdoing. And it comes in all shapes, sizes and political ideologies.

For instance, in a 1952 diatribe detailing real and purported activities of Illinois Gov. Adlai Stevenson, Sen. Joseph McCarthy argued that Stevenson had sought to help communists and would, if elected president, continue "suicidal, Kremlin-directed policies." He didn't allege that Stevenson was acting on behalf of Soviets, but he didn't have to -- it was accusation by innuendo.

The Soviets themselves were also great practitioners of innuendo, against dissidents in their population but also against the United States. In 1984, the Soviet media used innuendo to link the United States to the assassination of Indira Gandhi, stressing purported CIA links to the religious community from which the assassins came. Needless to say, the innuendo drew strong protest from the Reagan administration.