There is no US, there are just a bunch of interest groups. Some interest group definitely wants IA down. I wouldn't be surprised this is a paid attack.
Just for completeness sake and my own opinion based on my own witnessing of history, every political party of every government of every country would love to see all the archives gone. It's easier to twist the truth if one can memory hole reports and make the original source go offline or pressure them to change their words. There will always be individuals that archive stories they find interesting, but many stories are uninteresting until people learn what more may have been left out at a later time as part of a much bigger story. That is when the archives become a treasure trove and big archives sites are the first that people turn to for the original reporting. As a generic example, many news sites will redact what they knew to be false after the vast majority saw their misinformation but they can't redact an archive of their twisted truth. The internet has made it a little harder to control a narrative. It was so much easier to control when it was just a few big newspaper publishers that owned the smaller ones and a few big cable companies that owned most of the smaller ones. They would all literally parrot the same lines.
People in other parts of the thread say it's Israel. (Which certainly is "aligned with US interests abroad", as the powerful see it anyway). I think it is ridiculous conspiracism, right now anything anyone doesn't like they think Israel is behind it.
The crazy rise of conspiracism in our society in general, combined with Israel really is doing some nasty stuff (but not controlling everything you don't like), combined with the latent antisemitism in most conspiracism.
And I say this as a strong supporter of and activist on Palestinian rights and liberation. Free Palestine. (But there is no reasonable reason to think Israel is behind an IA hack. Or the fact that your mail came late, or anything else except what they're actually doing which is bad enough. Call your senators and tell them to vote for Bernie's JRD resolutions).
There are so many well documented awful things IL has done that most people don't know about (many still haven't even heard of the Sde Teiman video) that folks could be spreading the word about instead. It's a shame to see this kind of conspiracy mindset from at least some people who probably mean well. There is no harm in waiting a little bit for facts to emerge.