When a new leader takes the helm at an agency as big as the U.S. Department of Defense (DOD), it's common for recommendations to start pouring in from all quarters. Seemingly everyone and their uncle has an opinion on what challenges the new chief should tackle first. But not in recent memory has a string of previous deputy chiefs asked the new leader to do a total overhaul of our national security strategy—while acknowledging there is a limit to what we can pay.

Yet that's what a letter sent this week by five former deputy defense secretaries to newly installed Defense Secretary Chuck Hagel did. The letter asked Hagel to conduct a comprehensive review of our ability to deter our most pressing threats, but with an important new element: “The resources needed to pay for the posture must be determined,” it states. “The long-term federal budget outlook indicates the direction of change.” That direction points to lower spending on shiny new weapons as well as fewer forces and overseas wars to deploy them to, the letter says.

This approach is a major departure from existing doctrine that military strategy must be formed completely independent of fiscal reality. That doctrine is enshrined in the Quadrenninal Defense Review, the process created in 1997 to focus Pentagon thinking on our defense posture in relation to current threats. Though the original legislation stated the process must consider the budget “required to provide sufficient resources” to meet its goals, the language was amended ten years later to say the process should not be “constrained” by budgets. As we have long argued, it's exactly that kind of thinking that landed the Pentagon in the situation it faces today—trying to squeeze a bloated department into some tight budgetary britches.

The letter's departure from this doctrine may be uncommon, but these are uncommon times. The House of Representatives on Wednesday passed legislation to fund the government for the rest of the year that essentially validated the level of cuts created by sequestration, the across-the-board budget-cutting mechanism that everyone with a TV now knows will impact federal functioning. Though the legislation provided DOD with much more flexibility than other agencies—allowing it to move money into daily operations accounts—it still maintained sequester-esque spending levels. That's a big deal, considering all the hand-wringing in the multiple Congressional hearings on how sequestration would defang the world's most powerful military.

Unfortunately, the legislation also highlights another major contributor to Pentagon plumpness—Congressional pork. The letter mentions areas for savings (including health care), but mainly emphasizes the need to orient ourselves to the top threats of the future, i.e. cyber security and terrorism. Yet the House bill still adds money for Congressional priorities such as the Abrams and Bradley tanks, weapons built for the land invasions which the letter (and many military experts) say we won't be doing much of in the future.

Obviously, you don’t want the green eyeshades to completely dictate defense spending. But the strategy to meet threats to our nation has to be informed by budget constraints because the country’s fiscal situation is a threat as well. So, for all those who argue that national security decisions should not be touched by fiscal facts on the ground, this week's events should provide a wake-up call. Let's hope new leaders at the Pentagon and on Capitol Hill don't press the snooze button.