East Germany had a strategy for dealing with political opponents it referred to as Zersetzung. The FBI had a similar operation for political movements like the Black Panthers that's widely known as COINTELPRO. Both of those very evidently extremely successfully but ended decades ago.

We know that Russia still uses similarly subversive tactics internationally, especially in public messaging (popularizing multiple mutually contradictory narratives at the same time to compete with any attempt at "factual reporting", e.g. in its many justifications and descriptions during the early months of the invasion of Ukraine or following the infamous civilian plane crash during the "civil war" before that). There have also been credible accusations against China of employing disinformation campaigns to disrupt criticism. The first year of Israel's ongoing military campaign (initially in Gaza) also saw many people pointing out what they described as examples of Hasbara.

Under the first Trump presidency we saw the term "alternative facts" being used by US officials. Trump himself also popularized the term "fake news". Trump even bragged about "stopping Nord Stream 2", implying US involvement in the sabotage that so far has been considered to have been carried out by Ukranian nationals.

We also know (via Snowden and Wikileaks) that under the Bush and Obama governments the US actively used its intelligence apparatus even against its allies, at the very least for surveillance operations and infiltration (allegedly even industrial espionage). There's also the dissolved BND/CIA co-operation (via a Swiss proxy I think?) that came apart when the German BND was dissatisfied with the CIA's willingness to sell the faulty encryption technology they were disseminating to their shared allies to maintain cover for the operation.

During the Euromaidan protests (2014), the US diplomat was caught on tape exclaiming "Fuck the EU". During the Security Conference earlier this year, VP Vance explicitly promoted European far-right political movements and questioned the legitimacy of European countries' governments. Trump himself has repeatedly referred to the EU as an organization created for the specific purpose of screwing over the US.

In aggregate, the EU's nominal GDP right now is slightly higher than that of China. Germany alone has the third-highest nominal GDP in the world right now.

The US has for a long time at least engaged in hostile behavior against its own allies, including the EU. Trump has at several points been openly hostile against the EU. Trump has been promoting a policy of unilateral "peace through strength" over promoting cooperation and the pretense of mutual benefit and engaging in trade wars against all of its trading partners.

The US is acting as a hostile force against the EU and has redefined the EU as a hostile entity. It hasn't severed diplomatic nor economic ties to the EU but neither has it to China. Whatever you think the US might stomach to covertly do against China it therefore stands to reason they would have an interest in also doing against the EU. It's also worth considering that militarily China poses a much greater risk of retaliation and the EU is currently much more economically dependant on the US than China is (especially following the sanctions against Russia which previously acted as a major trading partner in the region and the rising tensions in the Middle East).

It seems extremely plausible to me that the US engages in activities intended to disrupt the integrity of the EU and consequentially the mutual trust and diplomatic relationships between EU member states. We know (with receipts) that Russia has been directly contributing to far-right nationalist anti-EU political movements throughout Europe prior to the invasion of Ukraine and even before Trump's first term and continues to support the anti-EU rhetoric of a "Europe of fatherlands" intended to fragment and individualize EU member states either as a "divide and conquer" tactic or at least to reduce their collective capability for actively opposing Russia's interests.

We don't know what the US has been doing or is doing beyond what it has been doing in the open. But given how much deeper the US's battle chest runs and how advanced its offensive technology (both from private industry and internally) that we know of is, it seems far more likely to me that this is not because it doesn't exist but because they've been better at not getting caught. Not to mention that European governments still refuse to treat the US with the same level of suspicion they treat China or Russia, thus making it far easier for the US to get away with actions even when they are caught. There's no need to worry about your covert operations becoming public when their target actively collaborates in supporting your operations against them.

> There's also the dissolved BND/CIA co-operation (via a Swiss proxy I think?)

sounds like Crypto AG[0]

[0]https://en.wikipedia.org/wiki/Crypto_AG