Originally Published: 13 FEB 23 00:19 ET

Updated: 13 FEB 23 04:48 ET

By Stephen Collinson, CNN

(CNN) -- A deepening national security mystery is threatening a political storm after US fighter jets scrambled three days in a row to shoot down a trio of unidentified aerial objects high over the North American continent.

The flurry of attacks on the unknown crafts came a week after the highly public tracking and ultimate downing of a Chinese balloon suspected of carrying out surveillance. Now, the thin details trickling out of the Pentagon and Capitol Hill about are making an already highly unusual international episode even more bizarre and confusing.

No one -- not the White House, the Pentagon or the government of Canada, whose airspace has also been infringed -- seems able to say exactly what is going on with these latest downed crafts. This raises questions for top military brass and US spy agencies as well as for the potential safety of civilian aviation. And it creates an information vacuum that Republicans are again using to question President Joe Biden's leadership.

The intrigue is also unfolding against a tense global situation, with already difficult relations with rising superpower China becoming ever more hostile and with the US leading the West in an effective proxy war against Russia in Ukraine.

"What's gone on in the last two weeks or so, 10 days, has been nothing short of craziness," Democratic Sen. Jon Tester of Montana said Sunday on "Face the Nation" on CBS, hours before an airborne object was shot down over Lake Huron.

"The military needs to have a plan to not only determine what's out there, but (to) determine the dangers that go with it," Tester said.

With the North American Aerospace Defense Command on heightened alert, US fighters have now blasted three objects out of the skies since Friday following the shooting down of the Chinese balloon off the South Carolina coast on February 4:

In the latest event, a high-altitude object was shot down on Sunday afternoon by an F-16 over Lake Huron, which lies between Michigan and Ontario. The Pentagon said the object was not assessed to be a military threat but was a flight hazard. But it did connect the craft to a radar signal picked up earlier over Montana, the home to US intercontinental missile silos and other sensitive sites.

On Saturday, a US F-22 warplane operating on the joint orders of Canadian Prime Minister Justin Trudeau and Biden fired a missile that took down an object flying at 40,000 feet over central Yukon in the far north of Canada. Canadian Defense Minister Anita Anand described a "cylindrical object" smaller than the Chinese balloon.

On Friday, an F-22 shot down another unidentified craft over Alaskan airspace. US pilots were able to get up around the object before it was shot down and reported that it didn't appear to be carrying surveillance equipment.

New questions raised by latest incidents

Even at the height of last century's Cold War, when US jets often headed off Soviet aircraft testing North American and European defenses, pilots weren't typically sent off to shoot down unidentified objects over the US and Canada. It's not normal for Americans to settle down for the Super Bowl with their president firing off orders to blast unknown objects out of the North American sky.

In fact, NORAD commander Gen. Glen VanHerck said recent objects shot down were likely the first "kinetic action" that NORAD or the US Northern Command had taken against an airborne object over US airspace.

So the events of the last few days do provoke serious national security and political questions that stretch far beyond the often narrow political battle in Washington, and that can only be assessed once more details are understood.

They include:

Are the latest incidents linked in any way to Beijing's espionage program described by the administration after the shooting down of the Chinese balloon and other reported crossings of other balloons over US territory? Any indication of successive Chinese breaches of US airspace would mark a serious twist in US-China relations already tested by a belligerent Beijing at what may be the start of a 21st century Cold War.

If they are not related to China, are the latest strange objects flying over North America linked to some other hostile power or group, corporate or private entity? Are they even connected to one another or are they simply the result of coincidences at a time of heightened awareness and tensions?

If the latter situation is the case, is NORAD now picking up more objects that are potentially hostile given a state of heightened alert after the Chinese balloon crisis? If the objects are suspicious is there a sudden spike in such flights or did such objects fly across the continent with impunity in the past? Given the already increased threat to civilian aircraft -- for instance from more low flying drones -- is this a new problem that that should concern the aviation industry?

Finally, what is the political impact of this string of incidents. Biden was criticized by Republicans for citing the possibility of injury to civilians or damage to buildings on the ground for waiting so long to shoot down the Chinese balloon earlier this month. He forcibly warned China in his subsequent State of the Union address that he would defend US sovereignty. Since then, his aides have styled his response to subsequent incidents as those of a decisive commander in chief. This shows that the White House understands the political peril in wait if Americans were to perceive he was not doing everything to defend the homeland.

The political blame game is heating up. On CNN's "State of the Union," GOP Rep. Mike Turner of Ohio, who chairs the House Intelligence Committee, linked the incursions of US air space to Republican claims that Biden is failing to protect the southern border and complained that senior officials were not briefing Congress enough. And he also adopted a novel critique of Biden given claims that the president didn't act quickly enough before.

"They do appear somewhat trigger-happy, although this is certainly preferable to the permissive environment that they showed when the Chinese spy balloon was coming over some of our most sensitive sites," Turner told Jake Tapper.

"I think one thing that this shows is certainly the fallacy of the argument of the Biden administration saying that the height of the Chinese balloon caused them to have no concern because certainly, as we know, whatever goes up can come down."

No comment from Biden

Biden, who didn't address the new intrusions at a black-tie event with state governors on Saturday, has yet to speak to Americans in person about the trio of incidents over the weekend.

But a senior official sought to play down concerns over the shoot-downs on Sunday evening.

"Because we have not yet been able to definitively assess what these recent objects are, we have acted out of an abundance of caution to protect our security and interests," said Melissa Dalton, assistant secretary of defense for homeland defense and hemispheric affairs.

"The spy balloon from (China) was of course different in that we knew precisely what (it) was. These most recent objects do not pose a kinetic military threat, but their path in proximity to sensitive (defense) sites and the altitude that they were flying could be a hazard to civilian aviation and thus raised concerns," Dalton added.

The lack of specificity is unlikely to quell speculation or partisan maneuvering in Washington. At the start of a new presidential election cycle and in a polarized political age when social media magnifies conspiracy theories, this odd series of incidents is heaping fresh pressure on Biden following recriminations after his decision to wait until the Chinese balloon had crossed the country before shooting it down over water.

New speculation and criticism could be premature as officials work to fully understand the sequence of events and more about the objects. CNN's Natasha Bertrand reported on Sunday that NORAD had recently readjusted the filters it uses to sift data, which had previously concentrated on spotting fast-moving objects below a certain altitude. Early warning filters had previously been set to avoid picking up other objects, including birds and weather balloons, a source briefed on the matter said.

CNN security analyst Juliette Kayyem said that this opening up of the "aperture" means that more objects are being identified.

"They are getting lots of positives that they did not get before. Most of that is going to be airplanes, whatever it may be," said Kayyem, a former assistant secretary at the Department of Homeland Security.

"What we can't answer now is, is this bigger aperture picking up lots of stuff that has essentially been forgiven, around in the skies, because it didn't pose a threat, or is it part of something organized for whatever surveillance?"

Another communications problem?

It's possible that in a unique, fast-moving situation, the government may not know much more than it is saying. But the piecemeal emergence of details is adding to the confusion. On issues including the Chinese balloon and the discovery of classified vice presidential documents at Biden's home and office, the administration has sometimes struggled to control a media narrative to its own political detriment.

There was more confusion on Sunday. Senate Majority Leader Chuck Schumer, a New York Democrat, said on ABC's "This Week" that the two objects shot down over Alaska and the Yukon were balloons but smaller than the original Chinese intruder, after saying he had earlier been briefed by Jake Sullivan, Biden's national security adviser.

The US Defense Department, however, later clarified that those two objects "did not closely resemble the PRC balloon" shot down last week. There are also signs that federal lawmakers may be getting information from military and local authorities that is incomplete, risking further confusion or politicization about what is going on.

Republican Rep. Matt Rosendale of Montana appeared to make a direct link Sunday on "CNN Newsroom" between the Chinese balloon and the latest objects, even if there is no confirmation so far that they are connected.

"It doesn't give me much safe feelings knowing that these devices are smaller," he said. "I am very concerned with the cumulative data that is being collected. ... I need some answers, and the American people need answers."

Such speculation may be premature. But fierce political debate over the balloon has clearly changed Biden's tolerance threshold for unknown aerial objects.

It's now a case of shoot first, investigate later.