Isaiah 43:2 promises God's presence specifically inside the extremity of danger: "When thou passest through the waters, I will be with thee; and through the rivers, they shall not overflow thee: when thou walkest through the fire, thou shalt not be burned." The Hebrew preposition beʿabar — "when thou passest through" — means in the crossing, in the going through. Not before the fire. Not after the fire. Inside it. This is not a promise of prevention. It is a promise of presence inside the worst of what combat produces.
Joel 2:25 offers a specific promise about restoration after prolonged loss: "I will restore to you the years that the locust hath eaten." Combat takes years — years of health, relationships, trust, and capacity. God's restoration promise encompasses what should have been and was not. Professional treatment for combat PTSD — therapy, medication, peer support — is one of the ways God provides the restoration he promises. There is no shame in using every means available.
Commentary is from a charismatic Protestant perspective, drawing on KJV text and public-domain sources including Spurgeon, Andrew Murray, and Matthew Henry.