I may be late to the party and this may be something that's been around for a while, but I've recently been hearing the phrase "worships is warfare" more and more.
You've been careful to make it clear that context is important in this question. I'm not sure yet about the context, but I'm seeing other places in Scripture where praise and worship and particularly singing brings about military deliverance by the hand of God.
Here's a few verses that came to mind,
2 Chronicles 29:27 KJV
[27] And Hezekiah commanded to offer the burnt offering upon the altar. And when the burnt offering began, the song of the LORD began also with the trumpets, and with the instruments ordained by David king of Israel.
2 Chronicles 20:21-22 KJV
[21] And when he had consulted with the people, he appointed singers unto the LORD, and that should praise the beauty of holiness, as they went out before the army, and to say, Praise the LORD; for his mercy endureth for ever. [22] And when they began to sing and to praise, the LORD set ambushments against the children of Ammon, Moab, and mount Seir, which were come against Judah; and they were smitten.
Psalm 66:1-5 KJV
[1] Make a joyful noise unto God, all ye lands: [2] Sing forth the honour of his name: Make his praise glorious. [3] Say unto God, How terrible art thou in thy works! Through the greatness of thy power shall thine enemies submit themselves unto thee. [4] All the earth shall worship thee, And shall sing unto thee; They shall sing to thy name. Selah. [5] Come and see the works of God: He is terrible in his doing toward the children of men.
Psalm 149:5-9 KJV
[5] Let the saints be joyful in glory: Let them sing aloud upon their beds. [6] Let the high praises of God be in their mouth, And a twoedged sword in their hand; [7] To execute vengeance upon the heathen, And punishments upon the people; [8] To bind their kings with chains, And their nobles with fetters of iron; [9] To execute upon them the judgment written: This honour have all his saints. Praise ye the LORD.