This is a Regional Event. This means that it is infinitely-repeatable. Progress depends on successful completion of each step. All players in the region may participate and all contribute to task completion. If time expires without completion then it goes directly to the final or cooldown task before the event begins again. Rewards are given at the end of each phase dependent on participation.
Just a word: Originally, any Public Quests contribution of Public Event Points you handed in during the "reset timer" would be lost into the void. At some point, they snuck in an update to prevent this. Now, if the reset timer is active, a message saying "MAINTAIN THE STATUS QUO" will be seen and the NPC will refuse to accept the turn-in until the Event restarts.
The expansion of the guardian production plant hindered the transport of supplies to the front line. In order to support the soldiers at the front line and let them fight without worry, the Alliance must bring the pipeline for supplies back in order soon.
Supports blocked - The situation is getting intense. Before the rear support arrives, the Alliance warriors have to hold out against the threat.