While Frum might be the kiss of death for a potential candidate, This piece on NPR yesterday morning implies some degree of concerted effort by the powers that be.
I didn't get this line,

"At the same time, the United States must pay for the long war against Islamic extremism. Yet the United States spends one third less now than we did 20 years ago on national defense -- only about four and half percent of national income."

Is he talking about GDP?  I thought Defense was half the Federal Budget?  Is he thinking it must be more?  (I suppose so, if he so fully jumps into the idea that it's our military that will be fighting the Jihadis..

In 2005 the DOD spent 19% of the 2.5 trillion Federal Budget. 474 Billion vs 2.472 in outlays. Plus emergency funds for Afgan and Iraq.
We spend a lot on national defense through the intelligence agencies, many of which are not funded through DOD. Then there's the Dept. of Homeland Buffoonery.  Also, the absurdity in Iraq has repeatedly been funded through special appropriations that are not part of DOD's budget. My guess is that we are spending at least $650-750 billion/year on national defense.
Frum repeated the same statistic in a give-and-take with Robert Reich on NPR yesterday evening.  That refers to 4.5% of GDP, not Federal spending.
Frum's argument was -- and I'm paraphrasing -- that 4.5% of our national income is a small price to pay for economic and political stability. He's right, of course. The biggest threat to the Western Military/Industrial machine is a scarcity of resources.