The <em>effect</em> of the <em>figurative language</em> in this passage, apart from <em>enriching the passage</em>, is <em>illustrating more vividly the reason why those would escape</em> (the strong connection that exists between those who escape and their friends.)
Explanation:
In the given passage, the figurative language is represented by the <em>phrase</em>:
<em>the strong cords of affection that bind them</em>
This is a metaphor: the <em>strong cords</em> refer to those <em>love feelings</em> that act as <em>connection</em> between the people escaping and their friends. The <em>metaphor of cords and binding</em> talks about <em>how close these people are and how those strong ties (feelings of affection) would make them overcome fear or danger and try to escape.</em>