Once upon a time it was understood - to hold a "vigil". A devotional watching, Wiki says. Devoted, yes. But a monitoring, too - an overwatch, as it were, of what matters to you. These days one finds the ubiquitous candlelight vigil held for practically every cat that kinks his tail. It has lost, I think, its deeper meaning. It is to do without a thing - rest, ease, comfort - in order to ensure something is noted, cared for.
Many of us are keeping a vigil on the Republic. We may not be able to do more than that. We may only find the smallest of chances to do so - to give that cover to the others in the field.
Thus, this. Note the hoo-ah when things get a bit too tight in the chest and that arm just a bit too heavy, bless him.
Leave it to the Marines to do it so smartly, so quietly, with so much dignity.