According to the report, which will be released early next week, the past year has seen a greater number of “significant terrorism plots” alleged than in any single year since 9/11 — including the attempt to blow up a plane over Detroit; two bomb plots in New York City; two bomb plots against federal buildings; the scheme to bring dozens of young men, mostly from the Minneapolis area, to join the Al-Shabaab organization in Somalia;  and the shootings at Fort Hood and at an Army recruitment center in Little Rock, which were the first killings attributed to jihadi terrorism on American soil since 9/11.

The CLS report also finds that more than half of the defendants in this year’s terror cases are American citizens and that the plots alleged by prosecutors concern increasingly serious charges, including a jump in alleged attempts to use “weapons of mass destruction,” meaning bombs.

Over the past several months, intelligence officials and security experts have warned that homegrown terrorism — as distinguished from conspiracies hatched abroad and executed by foreigners — represents a growing threat. Last May Dennis Blair, then the director of national intelligence,  delivered precisely such a warning at a Senate hearing where he presented his agency’s Annual Threat Assessment. Of special concern, said Blair, is the influence on young American Muslims of figures like Anwar al-Awlaqi, the American-born Islamist cleric located in Yemen, who has been targeted for assassination by U.S. special forces.

To assess the indigenous threat, the CLS researchers began by examining the long-term residency of individuals indicted and prosecuted for terrorism in the top 50 alleged conspiracies. They focused on defendants either born in the U.S. or who had lived in this country for 10 years or more, explaining that a decade is “long enough to allow for assimilation and can plausibly cover the formative years and alleged years of radicalization, as it does in fact for many of those already convicted.” Of the 156 defendants prosecuted in the top 50 plots, 127, or 81 percent, were homegrown – and at least 35 percent of those homegrown defendants had converted to Islam rather than being born into Muslim families.

“We have seen a slight spike in indictments of homegrown defendants in high-profile cases since last fall,” says the report. But further analysis shows that “homegrown terrorism defendants have been a constant presence in high-profile terrorism prosecutions” over the past nine years. The past year’s increase may only represent investigations that went on for several years before indictments resulted. Moreover, the reports says, “even if investigations are not ongoing, a defendant may spend years endeavoring to become a terrorist before being arrested.” Citing the case of Tareq Mehanna and Ahmad Abousamra, who were indicted last fall for seeking terror training in Yemen and Pakistan, the report notes that their jihadi journey began as early as 2002.

“For these reasons,” the CLS researchers concluded, “it is difficult to determine, as of yet, whether the spike we have seen can truly be attributed to an increase in homegrown terrorism — or whether the assumption that there is an increase stems instead from a generalized reaction to an increase in serious cases, and the first two successful attacks on U.S. soil since 2001, both perpetrated by homegrown terrorists.”

“The idea that we’re facing an increasing threat by homegrown terrorists is not necessarily the case, said Karen Greenberg, the center’s executive director. “But the more we condemn the Muslim religion, the more we misunderstand the actual nature of the threat, which actually comes from individuals of varied backgrounds who act — or try to act — for various reasons against American citizens or the US government.”

Greenberg believes that although homegrown terror is nothing new, the recent rise in domestic attacks on American Muslims may only attract more young jihadis — and provoke them toward further alienation and violence. Burning the Quran, vandalizing mosques, and portraying all Muslims as radical enemies of the United States imperils not only our troops abroad but everyone at home as well. 

Little details like that haven’t stopped the critics, especially as they’ve focused on the fact that Abdulmutallab was read his Miranda rights and allegedly stopped cooperating immediately afterwards. (In fact, Abdulmutallab was reportedly only Mirandized after he’d stopped talking.)

The White House has been fighting back, though, and as part of that effort, on Tuesday administration officials told reporters that Abdulmutallab has begun cooperating again. Methods softer than those the right would prefer were employed: Rather than waterboarding him, authorities brought some of Abdulmutallab’s family to the U.S. and allowed him to see them.

Sen. Kit Bond, R-Mo., the ranking member of the Senate Intelligence Committee, wasn’t happy about that public disclosure. In a scathing letter to President Obama, Bond wrote, “This information immediately hit the air waves globally and, no doubt, reached the ears of our enemies abroad.” He added that the news “has no doubt been helpful to his terrorist cohorts around the world” and said, “Consider the consequences of publicly disseminating sensitive information vital to the defense of the American people. I do not believe the American people want this information jeopardized to further political arguments.”

Bond does have one legitimate point in that he says members of Congress briefed on Abdulmutallab’s cooperation were initially told that it was important that fact a secret. But the information essentially came out anyway during Senate hearings this week, and that led to the administration’s decision to brief reporters.

Moreover, Bond has to know that he and his fellow Republicans aren’t blameless here. They can’t seriously expect to be able to take potshots at the administration’s handling of terror cases without prompting some sort of response — once you’ve started politicizing the issue, it’s hard to call for that politicization to stop. If the GOP’s worried about the consequences of that, it might want to take a hard look at its criticism of the way Obama’s handling terrorism and decide what are actually legitimate points that need to be raised and what’s just political grandstanding; all too often, it seems, the focus is much more on the latter.

Update: At his briefing on Thursday, White House Press Secretary Robert Gibbs called on Bond to apologize, saying, “The notion that somehow the White House, in conjunction with agencies involved in this interrogation, gave out classified information? I think an apology on that is owed, because it’s not true.”

Bond wasn’t having any of it, saying in a statement, “After telling me to keep my mouth shut, the White House discloses sensitive information in an effort to defend a dangerous and unpopular decision to Mirandize Abdulmutallab and I’m supposed to apologize?”

Separately, on his blog, Andrew Sullivan’s posted a letter from a reader who argues that Reid and Abdulmutallab shouldn’t have been Mirandized because it simply wasn’t necessary in their cases. We can debate procedure, but the letter’s worth reading if only because it’s a good, succinct explanation of the way Miranda works.

What a lot of people don’t understand — certainly what gets missed when people like Rush Limbaugh start worrying about hypothetically reading Osama bin Laden his rights — is that the right at issue is about self-incrimination. In short, if you’ve already given the goverment all it needs to convict you by, say, trying to blow yourself up in front of a plane full of witnesses, then the police can talk to you indefinitely without ever Mirandizing you; they just can’t use what you say during that interrogation against you in court. They can, however, still use it to investigate others, and potentially to prosecute them, though that depends on other circumstances as well.

The letter followed less than 24 hours after senior administration officials disclosed that the suspect had resumed talking to U.S. interrogators last week after breaking off his discussions the day of his arrest.

Holder said that the possibility of detaining Abdulmutallab in the U.S. military system under the law of war was explicitly discussed in the days following the arrest, including at a Jan. 5 meeting that included President Barack Obama and senior members of the national security team.

“No agency supported the use of law of war detention for Abdulmutallab, and no agency has since advised the Department of Justice that an alternative course of action should have been, or should now be, pursued,” the attorney general wrote.

In the interim, which lasted a few hours, investigators decided to read Abdulmutallab his Miranda rights when he returned, said a second federal law enforcement official. Both officials spoke on condition of anonymity because the investigation is ongoing.

Upon Abdulmutallab’s return, it became apparent that he was not inclined to continue talking to investigators, so they then read him his rights, said the second official.

The second official made clear that getting Abdulmutallab’s renewed cooperation has been an ongoing effort since that day.

In Detroit, U.S. Attorney Barbara McQuade declined to comment. A message seeking comment was left with Abdulmutallab’s lawyer, Miriam Siefer.

Several prominent lawmakers have argued that Abdulmutallab should have been placed in military custody immediately or undergone more questioning before being given a Miranda warning by the FBI. 

Principally, though, Obama’s remarks were about laying out what went wrong, where information fell through the cracks instead of being used to prevent Umar Farouk Abdulmutallab, the man accused of trying to blow up the plane, from boarding it in the first place. And they were about the steps he’s ordered, so far, in an attempt to correct the flaws in the system.

“It’s now clear that shortcomings occurred in three broad and compounding ways,” Obama said, continuing:

First, although our intelligence community had learned a great deal about the Al Qaida affiliate in Yemen, called Al Qaida in the Arabian Peninsula, that we knew that they sought to strike the United States and that they were recruiting operatives to do so, the intelligence community did not aggressively follow up on and prioritize particular streams of intelligence related to a possible attack against the homeland.

Second, this contributed to a larger failure of analysis, a failure to connect the dots of intelligence that existed across our intelligence community and which together could have revealed that Abdulmutallab was planning an attack.

Third, this in turn fed into shortcomings in the watch-listing system which resulted in this person not being placed on the no-fly list, thereby allowing him to board that plane in Amsterdam for Detroit.

In sum, the U.S. government had the information scattered throughout the system to potentially uncover this plot and disrupt the attack. Rather than a failure to collect or share intelligence, this was a failure to connect and understand the intelligence that we already had.

As for the corrective steps he’s ordered, Obama said:

First, I’m directing that our intelligence community immediately begin assigning specific responsibility for investigating all leads on high-priority threats so that these leads are pursued and acted upon aggressively not just most of the time, but all of the time.

We must follow the leads that we get, and we must pursue them until plots are disrupted. And that means assigning clear lines of responsibility.

Second, I’m directing that intelligence reports, especially those involving potential threats to the United States, be distributed more rapidly and more widely. We can’t sit on information that could protect the American people.

Third, I’m directing that we strengthen the analytical process, how our analysis — how our analysts process and integrate the intelligence that they receive.

My director of national intelligence, Denny Blair, will take the lead in improving our day-to-day efforts. My Intelligence Advisory Board will examine the longer term challenge of sifting through vast universes of — of intelligence and data in our information age.

And, finally, I’m ordering an immediate effort to strengthen the criteria used to add individuals to our terrorist watch lists, especially the no-fly list. We must do better in keeping dangerous people off airplanes, while still facilitating air travel.