文法問題

[!阿斯拉]

各位大大....
請問一個文法的問題喔..
作文黄金80题范文
Analysis of Issue Questions 2. nation 那一篇
第一段最後面有一句

While individual nations, like people, are at times willing to make voluntary sacrifices for the benefit of others, my view is that international coordination is nevertheless necessary in light of the strong propensity of nations to act selfishly, and because the problem is international in scope.

請問一下 and because 不都是連接詞嗎,為什麼可以放在一起用???
感謝感謝