The provisions of this article may be waived for any fiscal year in which the United States is engaged in military conflict which causes an imminent and serious military threat to national security
So when was the last time you remember that we weren’t “engaged in military conflict” because of the imminent threat to national security that drives The War on Terror? At no time in the last 10 years would this amendment have prevented deficit spending.
Notice also this out gives them the authority to ignore balancing the entire budget, not just giving allowances for going over the budget for military needs.
Need to bail out banks and car companies? Just declare a military threat, drop in a SEAL team, and pass any massive new government program you want in the meantime.