Fears of an alien invasion in the US took hold in the 1960s and 70s after reports of UFOs hovering over military bases flooded the nation.

Now, decades later, a UFO expert has claimed that the extraterrestrial spaceships did visit 'every major nuclear missile base' and continue to do so to this day.

Robert Hastings, who has interviewed many Army personnel about the bizarre sightings, said: 'The ones that are currently operational, have been visited repeatedly year after year according to the sources that I have interviewed.'

Hastings recently made waves when he revealed more than 120 former service members had come forward about their encounters with flying objects near nuclear weapon storage and testing grounds.

'A public, grassroots effort must be made in the interim to understand – as best as possible, using the data gathered thus far – the nature and intentions of those who pilot the UFOs,' Hastings penned in his recent book recounting the interviews.

'Or perhaps they have a use for our planet, let's say for scientific purposes, and know that global nuclear warfare will disrupt their data-gathering and/or experiments.'

In his book, UFOs and Nukes, he revealed that investigators are prevented from properly probing the cases because of dubious layers of classification.

One thing is for sure, however, it is 'obvious' that if there are extraterrestrial visitors, they are 'greatly interested in our nuclear weapons.'

Hastings' comments echo a study released in June that analyzed over 500 of the best-supported UFO cases from the heights of the Cold War, which concluded that 'this intelligence understands atomics, and they understand atomic weaponry.'

UFO reports over America's nuclear arsenal appeared to shift from sites where the bombs were made to missile silos and US air bases as the Cold War arms race grew.

The study was conducted by a retired US Air Force staff sergeant, data analyst affiliated with Harvard's UFO-hunting Galileo Project Ian Porrit and a research team.

The group focused on official military and police reports of UFOs from 1945 to 1975, avoiding poorly supported accounts and ambiguous newspaper stories, to focus on cases with multiple witnesses and signal evidence, like radar.

Their study, which only covered US cases, also used reports of UFOs spotted above non-nuclear army bases and nearby civilian centers to act as control groups to test against their findings of any UFO trends at America's sensitive nuclear installations.

The team found that data from 1948 through 1975, showed support to the idea that extraterrestrials, or some other intelligence, has methodically surveilled America's rise to a nuclear power.

'This intelligence understands the developmental cycle. They have some contextual knowledge of what they're looking at and what they're looking for,' Hancock told DailyMail.com, given these shifts in reported UFO sightings over time.

From 1948 to 1952, as America's production of atomic weapons first ramped up, waves of UFO sightings began cropping up over Washington state's Hanford nuclear production complex, as well as Los Alamos and other sites for the Manhattan Project.

'What we know now is that inside the Air Force for the first seven to 10 years they sincerely believed it was the Russians,' Hancock told DailyMail.com.

'And when they couldn't prove that,' he said, 'it became very political.'

From 1952 onward, their study found cases of UFOs probing near active nuclear weapons took precedence, with a wave of sightings around America's new intercontinental ballistic missiles (ICBMs) starting in the 1960s.

'When you get to those ICBM bases, from about 1965 to 1975, these things are occurring at night,' Hancock pointed out.

'And they are they are much more intrusive. They're very low altitude, they penetrate the security perimeters of the base,' he added.

Hastings' recent claims come just weeks after new government records surfaced other UFO waves near military sites, including 17 nights in December 2023 when swarms of UFOs were tracked over Joint Base Langley-Eustis.

These brazen penetrations over Langley — home to at least half the Air Force's F-22 Raptor stealth fighters — led to two weeks of emergency White House meetings.

To date, Langley's mystery UFOs have eluded identification by the Pentagon, police and even NASA's high-altitude research plane, the WB-57F, called in to investigate.

General Glen VanHerck, the commander with North American Aerospace Defense (NORAD), who led the mission to take down the infamous Chinese spy balloon in February 2023, described that Langley wave as unlike any other known case.

'If there are unknown objects within North America,' General VanHerck told the Wall Street Journal, 'go out and identify them.'

Senior ex-Pentagon security official Chris Mellon told DailyMail.com last week that the UFOs were 'swarms of smaller craft' released by 'motherships.'

He explained that was 'part of a much larger pattern affecting numerous national security installations.'

'Two of the notable aspects,' he said, 'are the fact our drone signal-jamming devices have proven ineffective and these craft are making no effort to remain concealed.'

Mellon told DailyMail.com: 'I make no claims regarding their origin, perhaps many are Chinese drones.'

'[But] in some instances,' Mellon took pains to emphasize, 'it is clear they want to be seen as though taunting us.'