This isn't yet decided. Microsoft and the DoJ are still arguing about this in the court system, which so far has ruled that the US government cannot compel Microsoft to release data it holds in Ireland. It's currently waiting for the DoJ to decide whether to take it to the Supreme Court: http://www.politico.com/blogs/under-the-radar/2017/01/micros...
Penalties for the US-based domestic entity to compel compliance of the off-shore entity would fall onto the domestic entity. The off-shore entity ALSO has to comply with whatever local regulatory regime they fall under.
Unlinking the two companies completely might satisfy what you appear to be angling for, but it would be, in essence, a potential competitor to Amazon at that point.
That sounds very dangerous. What would happen if Amazon simply had a 99% share, but 1% was held by another purely Irish company. Amazon might elect the board and the subsidiary might 'lease' intellectual property and capital from the parent company, but I don't see how you could argue it is subject to US law in any way.