What was Egwene trying to do to the chain before she was kidnapped?
Egwene’s plan revolves around standard siege warfare tactics. Surround your enemy and starve them into submission rather than killing them. That doesn’t work for Tar Valon because Egwene’s forces can’t stop supply ships from docking. When Egwene turned the chain into cuendillar it became one solid piece permanently blocking Northharbor and isolating Tar Valon from supplies.
