If you're serious about the job, a cover letter is mandatory. Real applicants take the time to learn about the position and explain why they are a good fit with their skills. People who just send a resume are just looking for a job and casting a wide net to see who bites. I've read thousands of resumes, and only hired one person that didn't send a cover letter.
Also, since I haven't seen it yet, have several people who you trust with grammar and punctuation review your resume before sending it out. Very few red flags compare on a resume like someone claiming to be "focused, detail oriented and professional " when they have typos on the page. The paper is your ambassador asking for a sit down negotiation - send it well groomed!
I'd be willing to give my perspective on your resume if you'd like another pair of eyes to review it. I do not have a mil background.