<p>In the first one, “they” should be “it.” The pronoun refers to the singular noun “sound.”</p>
<p>In the second one, “it” is an ambiguous pronoun. Though we can understand what the word “it” means here (something like “the intervention”), it does not refer to any actual noun in the sentence.</p>
<p>Actually in the 2nd one the it seems vague, but i’d most likely connect it to “governments” because not the intervene violates but the governments do, so even if it wasn’t vague, it should be plural.</p>