Who would be the most logical adversary who would cause this? Seems very unlikely for 3/5 to just happen.
Or as other commenters say, all three cables terminate in one city, so it could be a problem there.
> Undersea internet cable problems are not rare in Vietnam, which early last year saw all of its five cables disrupted for weeks.
Another possibility is that these cables provided an ideal training environment to test the capabilities of an adversary to cut off a region from the rest of the world. I'd think an adversary in wartime would cut all 5 cables. Vietnam could be the victim of an aggressor who just wants to practice/prove capabilities without much fear of repercussions.
I don't know who would benefit from crippling Vietnam's internet infrastructure today, but it could still benefit another nation to see/prove that it could.
Which is just code for “the government is doing it intentionally”.
These “problems” seem to coincide with major political events.
Tons of area to effect a break, and only need to break at a single point.
Attribution is difficult due to most of the sea being unwatched by most countries.
Economic impact, so less likely to result in escalation even if attributed.
Commercial shipping breaks cables all the time, so excellent plausible deniability.
End result: "a shame if something happened" situations like that Russian trawler doing back and forths across a Norwegian link.