However, the western executives that signed those deals, have long made their massive bonuses, it's all been paid out and some of those execs probably even retired. What do they care?
Such a great way to raid the company you manage at the expense of shareholders/employees.
Those agreements between private entities are almost certainly not public. However, I found a press release by Siemens AG [1] that says "Part of the contractual terms and conditions involves support and technology transfer in connection with production of the trains." In another press release [2], a Siemens VP is quite chipper about this: "Siemens is even more confident to support the development and modernization of Chinese railways and transfer highly advanced and proven technology of international standard to China"
I don't think you can speak of "wholesale theft" in this case of a voluntary deal.
[1] https://www.siemens.com/press/en/pr_cc/2005/11_nov/tstr20051...
[2] https://www.siemens.com/press/en/pr_cc/2006/04_apr/tstk20060...
The CEO of Siemens at the time was Klaus Kleinfeld. The bribery scandals were so bad in 2007 that he was forced out, and forced to settle with Siemens, 2 millions euros.
https://en.wikipedia.org/wiki/Klaus_Kleinfeld#Bribery_invest...
Now, ostensibly, these were scandals about Siemens bribing other countries. Do you think people at Siemens, with such high moral integrity, managed to pocket some bribes themselves?
Perhaps in exchange for handing over valuable IP? What's a signature or two between friends.