The article neglects (inadvertently I'm sure) two important points:
1. It looks at defense spending as a percentage of discretionary spending, but fails to look at it as a percentage of total spending. Do you think that, maybe, just maybe the author did so because it furthered his narrative?
2. The author states that defense spending has increased from $300 billion to $700 billion in the last ten years. Well, duh. He uses 2000 as his base year, a year in which we were not involved in any wars. Since then, we've fought two (and are still fighting one). I know this will be a shocker, but wars are expensive.
But the author is right about one thing: we need to eliminate (or at least reduce) all wasteful government spending.