Donald Trump in New York on Saturday. (Rich Schultz/Associated Press)

Regarding the Oct. 17 news article “Jeb Bush fires back at Trump for criticizing brother about 9/11”:

Republican presidential candidate Donald Trump has made outlandish comments about how then-President George W. Bush handled the Sept. 11, 2001, terrorist attacks, both before and after.

Then-Director of Central Intelligence George Tenet “knew in advance there would be an attack and he said so ,” Mr. Trump said. Before 9/11 there was definitely “noise” about possible attacks, just as there was before Pearl Harbor. But in both instances, discerning useful signals from the noise beforehand proved to be no easy matter. Hindsight is, of course, 20/20, and it is never that difficult to connect the dots after the fact; but 9/11, just like Pearl Harbor, was a genuine strategic surprise. I believe history will judge Mr. Bush on the effectiveness of his response to that catastrophic attack.

As someone who served successively as U.N. permanent representative, ambassador to Iraq, first director of national intelligence and finally deputy secretary of state during the Bush administration, I witnessed the intelligence, courage and decisiveness with which the president dealt with the immediate aftermath of 9/11 and the ensuing consequences.

I believe that comments such as Mr. Trump’s debase the level of political discourse that is badly needed at a time when there is a dramatic resurgence of terrorism in the Middle East and the level of political instability there is dramatically greater than it was when Mr. Bush left office.

John D. Negroponte, Washington

Would that there was a WASPish equivalent for the Yiddish word “chutzpah.” That term would nicely apply to Jeb Bush’s grossly tone-deaf claim that his brother George W. Bush “kept us safe” during the course of his presidency. The Sept. 11, 2001, attacks, Hurricane Katrina and the 2008 financial crisis were the most destructive and harrowing assaults on U.S. domestic security since World War II. The Bush administration’s ineptness in each inflicted unprecedented levels of peril and loss on this country.

Perhaps the privileged dynast Jeb Bush felt safe during those times, but many Americans paid huge costs in blood and property and a sense of security. Anybody and everybody running against Mr. Bush for the GOP presidential nomination should make him convince us that he is, unlike his brother, someone we can trust with the security and well-being of our families.

Jon S. Ketzner, Cumberland, Md.

Republican presidential candidate Donald Trump accused competing candidate Jeb Bush of wrongly defending his brother’s reputation regarding protecting the United States from the Sept. 11, 2001, attacks. The situation does not have an easy answer. Some agencies did not effectively handle information they had regarding the terrorists.

The “captain of the ship” stands responsible for the success or failure of those who serve under him. President George W. Bush did not cause Hurricane Katrina, but he is responsible for the ineffective government response to it. Similarly, President Obama is responsible, good or bad, for this government’s response to events in Syria. The complexity of these major decisions mitigates the captain’s accountability.

Jan Polissar, Bethesda