请求高手帮忙看看语法，不胜感激！

When pressure of circumstances, danger, or inward strife makes recognized and prolonged guidance necessary to a scial democracy, the form its government takes is that of a rudimentary monarchy established by election or general consent.

此句话中划线部分makes,是单数，是否因为pressure of circumstances, danger, or inward 主语是用or 连接？

划线部分established是语is 构成被动态谓语还是monarchy 的定语从句部分？如何看出？