What is the subject of "in line with……" in this sentence?
"There have been signs in recent months that Xi Jinping and his colleagues have decided to toughen their stance on Taiwan in line with their broader attempt to impose conformity and centralisation and to impose order on China’s peripheral regions of Xinjiang and Tibet."

1. What is in line with their broader attempt to impose conformity and centralisation? "The decision to toughen their stance on Taiwan" or "their stance on Taiwan"?

2. Can I restructure the sentence in this way: In line with their broader attempt to impose conformity and centralisation, Xi Jinping and his colleagues have decided to toughen their stance on Taiwan.

Thanks.

Question

What is the subject of "in line with……" in this sentence?
"There have been signs in recent months that Xi Jinping and his colleagues have decided to toughen their stance on Taiwan in line with their broader attempt to impose conformity and centralisation and to impose order on China’s peripheral regions of Xinjiang and Tibet."

1. What is in line with their broader attempt to impose conformity and centralisation? "The decision to toughen their stance on Taiwan" or "their stance on Taiwan"?

2. Can I restructure the sentence in this way: In line with their broader attempt to impose conformity and centralisation, Xi Jinping and his colleagues have decided to toughen their stance on Taiwan.

Thanks.

Answer

Very tricky sentence. I'd say that as worded, the "stance on Taiwan" is in line with "their broader attempt" since "stance" and "attempt" are what are the same. If you change the sentence to "their decision to ...." Then I'd say that "decision" and "attempt" are the parallel words.

Your restructured sentence is great. Simpler and clearer.

Answer

"In line with" here is an adverbial phrase modifying the verb "toughen" in its infinitive form.

We would not be looking for a "subject" for an adverbial phrase.