赞同邹德浩老师【只有1个介词叫介词短语，2个/2个以上介词叫复合介词】解答观点，我补充一点供网友参考

in power/in one's power/within one's power主要有以下2种用法

【1】当权/执政 (power英文解释political control of a country or an area 统治；政权)

The present regime has been in power for two years.现政权已经执政两年了。

The men in power have all the nasty impulses.  当权诸公也有种种见不得人的想法.

【2】控制力 (power英文解释the ability to control people or things 控制力；影响力；操纵力)

Although it is not in his power to do so, he said he would rebuild the Air Base.

虽然这超出了他的能力范围，他还是说他会重建空军基地。

Your debt situation is only temporary, and it is within your power to resolve it.

你的债务情况只是暂时的，你有能力解决好。