Relative Adverbs

Question

Here's part of an article in LSAT:

"As a result, an astonishing variety of information is able to flow unimpeded across national and other political borders, presenting serious difficulties for traditional approaches to legislation and law enforcement, to which such borders are crucial."

I always have a hard time with these "preposition + relative pronouns" structure. I even doubt if this here is relative adverbs. In the partial article above, what does the "which" point to? I think the "such borders" means "other political borders" mentioned earlier. I guess that "which" means "legislation and law enforcement". Please correct me grammar-wise.

Answer 1

This sentence is convoluted, and I initially parsed it the same way. However, which appears to represent traditional approaches, because traditional approaches is acting as the indirect object of the participle phrase presenting serious difficulties for traditional approaches.... The meaning is conveyed, regardless, since the reader undestands that borders are crucial to legislation, law enforcement, and the (implicitly understood to be overwhelmingly common) tradition approaches to them.

It's simpler to unpack if we invert the final phrase, as explained here: https://english.stackexchange.com/questions/322836/how-to-correctly-apply-in-which-of-which-at-which-to-which-etc. We can use context and semantics to help us. Here are some candidate sentences:

1. Such borders are crucial to presenting serious difficulties for traditional approaches to legislation and law enforcement.
2. Such borders are crucial to serious difficulties.
3. Such borders are crucial to traditional approaches to legislation and law enforcement.
4. Such borders are crucial to legislation and law enforcement.

(1) and (2) can't be right, because a variety of information being able flow led to the difficulties, not borders. The article calls out traditional approaches to legislation and law enforcement, which hints that there may be some other kind of approaches to legislation and law enforcement. This implies that (4) is too broad, and so we're left with (3).

As a native speaker, though, I required this semantic context to arrive at the correct syntactic structure. It could be rewritten more clearly. Here's my stab at restructuring and rewording:

As a result, an astonishing variety of information can flow unimpeded across political borders, seriously hindering traditional approaches to legislation and law enforcement that rely on such borders.