An honor guard opens the door as Russian President Vladimir Putin enters a hall to attend a meeting with members of the Presidential Council for Civil Society and Human Rights at the Kremlin in Moscow, Russia, on October 1. Reuters/Yuri Kochetkov One of the major characteristics of Russian President Vladimir Putin's post-Ukraine crisis decision-making has been his willingness to use his military as a blunt instrument of the Kremlin's policy.

Between a multibillion-dollar military modernization push, expensive and high-profile new weapons development, and military operations in Syria and Ukraine, Putin has attempted to project conventional military strength while demonstrating an actual willingness to use force.

But there's one big problem: The Kremlin just can't sustain its current level of military investment.

According to Reuters, Russia plans on slashing its military budget by 5% in 2016. This would be a notable number in any era, and constitutes the largest cut in defense spending in Putin's presidency. It's especially important in light of Russia's current roster of expensive military policies.

At the moment, Russia is developing a fifth-generation fighter jet, building its massive T-14 Armata main battle tank, and procuring new warships and submarines. Russia is undertaking a reported $400 billion military modernization push, and constructing a string of bases across the Arctic Circle.

Moscow is carrying on an air campaign in support of the Syrian dictator Bashar Assad, sustaining the separatist rebellion in eastern Ukraine, and waging incursions into NATO and allied waters and airspace, a campaign that's involved the largest presence of Russian submarines in the north Atlantic since the end of the Cold War.

Russia is replenishing its hardware and frequently turning to its military to implement its foreign policy.

Yet the country's economic situation requires deep cuts in military spending at a time when the Kremlin can least afford them.

Russian military vehicles make their way to Red Square during a rehearsal for the Victory Day military parade in May 4. Alexander Zemlianichenko/AP

The cuts only underscore just how dire Russia's economic situation is at the moment.

Last year, the Russian economy contracted 3.7% in the face of international sanctions, plunging oil prices, and a ruble valuation crisis. The country's expected to remain in an economic trough this year as well, with expectations of the economy contacting an additional 1% this year, according to Reuters.

Putin's challenge is to sustain an aggressive foreign policy that has been at the core of his popular appeal — despite the political and economic cost of propping Assad or cleaving off parts of eastern Ukraine.

The cuts in defense spending exposes one of the biggest contradictions in Putin's policies. Putin's influence and appeal are rooted in military expansion and adventurism, but this approach leaves the country more isolated and less capable of sustaining a military in the first place.