Your burden to pray for those in authority and for those who serve in the armed forces is biblical and right, and it is good that you bring it before the Lord with thanksgiving.
Scripture urges that prayers, petitions, intercession and thanksgiving be made for all people, for kings and for all who are in high positions, so that we may live peaceful and quiet lives in godliness and dignity. That kind of praying is good and pleases God, who desires all people to be saved and to come to the knowledge of the truth. The Lord Jesus has also commanded His people to go and make disciples of all nations, and a measure of peace and order in society helps to keep the door open for that gospel to be proclaimed freely and clearly.
A central need for every leader, whether in civil government or in military command, is wisdom. Wisdom is not hidden away. Like a voice calling in the street and at the gates of the city, it invites everyone to come and receive. Wisdom is the principal thing, so we are told to get wisdom and with all our getting to get understanding. If we must choose between mere knowledge and wisdom, wisdom is better, because wisdom is the right use and application of knowledge. It will preserve and keep the one who loves it. Scripture says the Lord by wisdom founded the earth and by understanding established the heavens, and all things that people desire cannot be compared to wisdom. It is better than rubies and dwells with prudence.
The beginning of that wisdom is the fear of the Lord, learning to hate evil and to walk in reverence before Him. There is a wisdom that is earthly, sensual and self serving, and it shows itself in envy, strife and confusion. That is not the wisdom from above. The wisdom that comes from above is pure, peaceable, gentle and full of mercy, and its fruit can be seen in a life. The wisdom of this world, for all its learning, did not lead the world to know God. God has shown the wisdom of the world to be foolishness, and our faith is not to rest in the wisdom of men but in the power of God. In Christ are hidden all the treasures of wisdom and knowledge.
This is why the prayer of Solomon is such a model. When he could have asked for riches or honor, he asked for wisdom to lead well, and God was pleased to give it and to add other blessings. In the same way we can ask God to give to those in authority a heart that fears Him and seeks His counsel, not only natural knowledge or strategy but heavenly wisdom that loves righteousness and justice.
We also join you in asking for protection. The spiritual battle is real, and we wrestle against the rulers and powers of darkness. We can ask the Lord to restrain evil plans, to bring confusion to wicked schemes, and to command His angels to encamp around those who fear Him and to deliver them. As you noted, the psalms speak of His shelter and refuge, and the letter to the Ephesians calls us to stand clothed in the armor of God and to keep praying at all times for all people.
May the Lord grant wisdom and understanding to all who bear responsibility, guard those who serve at every level, restrain the evil one, and grant peace where it is possible so that the good news of salvation through Jesus Christ alone may be spoken openly and bear fruit. The gospel, when truly received, brings life and transformation, and we pray that many will hear it and be saved.