How much better, if at all, would todays "special forces" fare against the Vietcong, masters of asymmetric jungle warfare?

They our special forces would be better having learned by experience.

Having “home field advantage” in a mountainous jungle terrain is a pretty major factor in favor for the Vietcong. The kinds of advantages modern tech affords today’s special forces such as night vision, FLIR, high resolution satellites or drone surveillance are largely negated by the canopy of the jungle and dense vegetation. I’m certainly no expert, but my hunch is that it would still be a very difficult mission for modern day special forces.

The technology of this day would likely negate the advantages of the past.

They’d probably get nuked.

Americans weren’t very good at jungle warfare that’s why they resorted to defoliants such as the notorious Agent Orange. I don’t think the American special forces have improved much over the years but defoliants may have.

No better, potentially much worse.
They should stay home and mind the issues in their own country.

Viet Cong in 1974 versus 2023?

You can’t make any sort of reasonable comparison. In 1974, the Cong were under strong communist rule and were fighting for their territory, which of course the regained.

Vietnam today is a communist country, but has moved strongly to become industrial / manufacturing and no longer agricultural. The Cong from 1974 are all in their 60s and 70s, and there is not a significant military today.

So if you’re asking – how would the 2023 US Army do against the 1974 Viet Cong? – the answer is ‘better than it did’ but still would take losses.

If you’re asking – how would the 2023 US army do against the 2023 Vietnam army – the US would win in a rout.

@elbanditoroso What about the 2023 US Special forces vs. the 1974 Viet Cong with access to modern-day stuff (like cell phones and commercial drones, etc.).

@gorillapaws too many assumptions. Would the Cong have retained its network of tunnels all over Vietnam in good shape, so they could be used?

If a 1974 Cong had access to 2023 technology, it would be a closer fight. But there are lots of details that would make a difference.

@elbanditoroso US Special forces go back in time to 1974 bringing any/all equipment and fire support they want. 1974 Viet Cong have access to 2023 Amazon that will put together anything they want to go back in time for the fight as well as instant knowledge of what it is and how it works.

The US just lost two twenty-year wars against guys in sandals with AK-47s and IEDs.

As @gorillapas writes, home field advantage is huge. One side is miserable guys in a weird place getting shot at from all directions. They have no friends among the locals and can’t go outside their compounds without armor.

The other side is protecting their homes and families from invaders.