Leadership cannot remove or control tension (we live in a fallen world). It can try to manage it and show how to cope with it. This may be why leaders need to have patience.
The messiness of our world means that people often disappoint and also fall into conflict. That is not news, just read the news. But leaders really cannot remove tension or entirely control it. They can work at the circumstances that produce it (the ones where they have some access). They can dissapate it in certain situations. But more often than not, a leader simply has to live with the tension and do their best to cope with it and engage it. This is often the case in choices a leader makes that will inevitably disappoint some while pleasing others. Hopefully the leader is clear in why the choice has been made and in articulating to others why it was made. That ability to engage the tension and face it openly often can yield respect even from those who might not agree with the choice. The evidence of engaging the tension and being aware of it can help others to turn the corner and move on. That is not to say the disagreement will disappear. But it may alter the dynamics of how discussion proceeds. That kind of impact is also a part of leading, especially in the face of tension and pressure.