Granted, the soldier on the ground is also responsible for following orders and not exceeding necessary force to accomplish the mission, not taking more lives than necessary. But the soldier simply fights on behalf of countrymen; he or she has no control over what wars are fought or what missions within the wars are directed. Legislators and civilian leaders in the Executive Branch of our government make those determinations for the most part, or high ranking flag officers. In the end, though, all shall give account of themselves to a Holy and Righteous God (Romans 14:12), and God sees all things (Hebrews 4:13), so any unnecessary taking of life or lives will be judged by God.
But for the most part, followers of God usually do not need to resort to force to do God’s will. If we are truly guided by God and have spent time daily with Him and brought every thought into obedience to Christ (2 Corinthians 10:5), then we will be guided by God’s Spirit, using instead spiritual tactics of love and peace, and if there is force needed, we let God fight that battle so that the victory and the glory goes to Him. We should always remember that our spiritual victories are “not by might, nor by power but by [His] spirit” (Zechariah 4:6). We fight using His guidance, His ways, and we fight only where and how He directs us. Moreover, “we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age, against spiritual hosts of wickedness in the heavenly places” (Ephesians 6:12). While we may see an angry or contentious person in front of us, you can bet that Satan and his demon followers are usually guiding the possibly spiritually unarmed person (not saved by Jesus or not sufficiently yielded to God’s guidance in their walk with Him).
So we should not allow ourselves to be angry at this person in front of us, realizing that they “know not what they do” (Luke 23:34) and are merely acting out of ignorance in the same way that we might act had God not revealed His truth to us and taught us His better ways (1 Corinthians 2:10). Knowing this, we should always respond as much as is within our ability with love, not responding in kind as the world would, not responding in our emotions, and “not returning evil for evil or reviling for reviling, but on the contrary blessing, knowing that you were called to this, that you may inherit a blessing” (1 Peter 3:9). We are called as Christians to a higher calling, not walking in our flesh and simply responding as our sinful nature might guide us, but walking in the spirit (Galatians 5:16, Ephesians 5:8), walking in the way of love (Ephesians 5:2) as taught in Scripture and as taught to us by the Holy Spirit in our times of Bible reading, meditation on Him and His ways, and prayer.
I pray that you would walk in peace and joy, enjoying fellowship with our Boundlessly Loving, Amazing God.