If I'm reading this op-ed from Danielle Pletka and Thomas Donnelly correctly it sounds like they don't want the Republican party (or the Tea Party) to cut defense spending. Which is fine, so far as it goes. But they also seem to insist that the desire not to cut defense spending is somehow tied to protecting "freedom" at home and abroad.
Is there a correlation between U.S. defense spending and global freedom? There doesn't appear to be: in the period 1990-2000, as U.S. defense budgets fell, the number of countries ranked "free" by Freedom House grew slightly. Since 2000, as defense budgets grew, the number of countries ranked "free" stayed pretty much the same - the trend lines toward greater global freedom had actually turned negative during the years 2006-2009.
In other words, if you want to make an argument for why the U.S. should continue to devote plus or minus X amount of dollars to defense expenditures, I don't think "freedom" has much to do with the case one way or the other.