foreboding extension [closed]

"Direction" has to be taken to mean "the general way in which a person or thing develops" (OALD, 3) or rather, according to SOED, 6b,

"fig The course of development of thought, effort or action; a distinct tendency or trend; linear or consistent progress".

There are two options; one can give to "extension" the rather natural sense of "increase in the activity" (OALD, 1). However, this is not logical: there is no question here of this event (murder) and associated social phenomenon being an increase in activity of the direction to come.

There is also the possibility to consider Manson's philosophy and the murders he is associated with as an offshoot phenomenon in the anti-establishment movement and call it an extension, as in OALD, 6, but figuratively, or as in SOED, 8b, (also figuratively).

8a (An) increase in length or area. b A part of something that extends or enlarges it

It could then be "a foreboding offshoot of the direction…" but that is not logical either. The thinking seems flawed and the writer's thought would have been rendered faithfully rather this way.

• …these murders were not a foreboding extension of the direction of the anti-establishment movement as a foretaste of that in which it was going

In other words, these murders were not a dangerous slide in part of the movement and could not have been seen as premonitory of the course of development of the anti-establishment movement as it would end up.

In the following fuller extract (doclecture.net) the bold type sentence shows "foreboding extension" to be a term that connotes narrowly "ten-or twenty-year extrapolation of the direction in which the counterculture was going". An extrapolation is (SOED) "gen a prediction on the basis of known facts or observed events"; therefore, the extrapolation can only be on the direction to come.

A view that’s enjoyed some currency is that the murders represent a watershed moment in the evolving social structure of our society. This view holds that the Manson case was the “end of innocence” (the ’60s mantra of love, peace, and sharing) in our country, and sounded the death knell for hippies and all they symbolically represented. In Joan Didion’s memoir of the era, The White Album , she writes: “Many people I know in Los Angeles believe that the Sixties ended abruptly on August 9, 1969…and in a sense this is true.” Even now, in 1994, ABC’s Diane Sawyer endorses this notion when she says the Manson murders “brought an end to the decade of love,” and “something changed in the heart of America” with the murders.

Others feel, less extravagantly, that the murders were emblematic of the counterculture flower gone to seed. As Time magazine said in 1989 on the twentieth anniversary of the murders, the three female killers were “any family’s daughters, caught up in the wave of drugs, sex and revolutionary blather that had swept up a generation of young people.”

Or, some thought for a time after the murders, perhaps Manson and his disciples represented a ten-or twenty-year extrapolation of the direction in which the counterculture movement was going. And so forth.

All of these hypotheses seem to be devoid of supporting empirical evidence. For instance, although the Manson murders may have hastened its descent, the Age of Aquarius, of which Woodstock (one week after the Manson carnage) was at once its finest hour and last gasp, was already in decline. As the decade of dissent and raw excess approached its denouement, the movement’s mecca, Haight-Ashbury, was in ruins, and America had begun its retreat from the war in Vietnam—the political raison d’être fueling the movement. Moreover, Manson and the madness he wrought did not reflect the soul of the late ’60s, when admittedly the anti-establishment movement had reached a feverish crescendo. That movement indeed wanted a new social order, but largely one brought about by peaceful means. Manson advocated violence, murder, to change the status quo. As pointed out in the body of this book, though Manson was a hero to some, according to surveys at the time a majority of young people whom the media labeled “hippies” disavowed Manson, stating that what he espoused, i.e., violence, was antithetical to their beliefs.

And we certainly know, from the unerring rearview mirror of twenty-five years later, that Manson and these murders did not represent a foreboding extension of the direction in which the anti-establishment movement was going.