The blue meter to the left of your MechWarrior portraits represents your Lance’s overall morale on the field. Morale is continually gained, primarily by positive actions (damaging and destroying enemy ‘Mechs) increase your Morale. Regardless of events, your lance also gains some Morale at the start of each turn.
When the Morale Bar fills completely, you can inspire one of the MechWarriors at any time. A MechWarrior is inspired for the turn's duration, attacks ignore COVER, GUARDED, and EVASIVE bonuses, and all attacks gain a 95% chance to hit, except for long-range weapons that are inside their minimum range.
Each time either player uses Inspire, the rate of Morale gain for both players increases - Morale Bars fill quicker. This effect is cumulative.