Mitt Romney and Paul Ryan want to cut domestic spending in order to increase military spending. Regardless of whatever else may be true - that is, regardless of whether you think more military spending is otherwise a good idea, or how you feel about the public services that would be axed by greater domestic cuts - their plans to cut domestic spending in order to increase military spending would cost hundreds of thousands of American jobs.
How many jobs? A plausible estimate is that their plans to cut domestic spending in order to increase military spending would cost at least 530,000 jobs.
What does 530,000 jobs mean in the context of the U.S. economy? According to the Bureau of Labor Statistics, there are currently about 12.8 million unemployed out of a labor force of about 155 million, for a measured unemployment rate of 8.3%. If an additional 500,000 people were employed today, there would be 12.3 million unemployed and the unemployment rate would be 8%.
By comparison, in September 2011, economist Mark Zandi of Moody’s Analytics estimated that if two stimulus measures were allowed to expire the end of 2011 - the 2% employee payroll tax holiday and the emergency unemployment insurance program - that would cost 750,000 jobs in 2012. As you may recall, there was a huge fight about whether those two stimulus measures should be allowed to expire. The job loss from replacing military cuts with domestic cuts is roughly of the same order of magnitude. If it was worth fighting about saving those 750,000 jobs by extending the stimulus, then it's worth fighting about saving 530,000 jobs by not replacing military cuts with domestic cuts.