leadership作“领导层,领导人员”解时是集合名词,当其作主语时,谓语动词可用单数形式,也可用复数形式。

Britain has lost her leadership in the shipbuilding industry.英国已丧失在造船业的领导地位。
What the country needs most is wise leadership.这个国家最需要的是英明的领导。
The leadership of the movement is/are in agreement on this issue.这一运动的领导层对这个问题的看法一致。