The Brussels bombings make it abundantly clear that a priority for all states should be defeating radical extremist terrorism — together. While Russia's actions in Syria and elsewhere have yet to demonstrate that this is Moscow's top priority, we may be close to a resolution of the civil war in Syria — a major breeding ground and operational area for the Islamic State group and other radical Islamists. If that is the case and we derive the right lessons from Syria, we could also achieve a favorable resolution of the war in Ukraine.

With its announcement three weeks ago that Russia will draw down its forces in Syria, the Kremlin appears to have made the calculation that time in Syria was not on its side. Continuing its military engagement would have brought increased costs and risks, and so it was time to exercise leverage not just on the Syrian opposition and its supporters, but on President Bashar Asad. Moscow appears to be effectively backing the UN-brokered peace talks in Geneva. It may now be possible to reach a compromise regarding the future of Asad and ultimately to bring peace to Syria.

If that is indeed how Moscow sees things, there may be some lessons for how we deal with Ukraine.

In Syria, in the face of the Russian intervention, we increased military support on the ground, and in the air — demonstrating our resolve to counter Asad, Russia and Iran militarily over the long haul. Our military assistance has been incremental and no doubt we can do more, but the administration has made clear that the United States stands firm with the Syrian opposition. Without a peaceful compromise, Russia will have to continue some level of military operations, indefinitely racking up monthly operational costs, and assuming ongoing risk of more Russian lives lost, more incidents with Turkey (like the shootdown of a Russian Su-24 aircraft in November over Turkish airspace), and possibly military reversals.

Likewise, in Ukraine, increasing our military support may also be the way to ensure implementation of the Minsk agreements and what should be a critical early step in doing so — a Russian military withdrawal. In Russia's war against Ukraine, the Kremlin assumes time is on its side, expecting Ukraine's economy to deteriorate, and hoping and working for the collapse of the government. But there is one area where they must know time is not on their side. It is in the military arena where — with US and other allied assistance — time is on Ukraine's side and working against Russia. The training that the US and NATO allies are providing to Ukraine's military and security forces ensures that over time the military gains strength and can potentially deter further Russian aggression.

President Barack Obama's budget request for 2017 includes $335 million for Ukraine to address bilateral defense priorities including training (and equipping as part of the training program), medical equipment, communications gear, electronic warfare and tactical UAVs. Congress has also appropriated $75 million in combined State Department and Defense Department (DoD) accounts for additional training for Ukrainian security forces. Such funds were used in 2015 to train the Ukrainian National Guard — selected by Kiev as the priority forces for training at the time. If Congress approves and the administration moves quickly to get the training going, we can continue to make progress towards building a stronger, more modern, professional and accountable military for Ukraine.

But training takes time and personnel, so we should invite our allies who are already helping — Canada, the United Kingdom, Poland, Lithuania and others — to do more, bring more allies willing to contribute substantially into the effort and consider using private contractors. Increasing the number of capable trained military, national guard and border security forces quickly can create a "bow wave" of personnel who have these new skills and perspective and thereby effect real change faster and more durably. Several years ago, DoD used this approach to design a program to train cadets from a NATO country in US National Guard schools. It ensured a large enough cohort would get trained fast and return to their the armed forces to effect change — instead of being swallowed back into the big old-school armed forces, as was the case in Ukraine in the past and for other transitioning countries. (The National Guard ran out of funds, so the program did not survive to achieve its ends, but the concept was sound.)

The United States should also use the opportunity now — before any new Russian surprises in Ukraine — to provide anti-tank missiles to Ukraine. The possibility that greater numbers of Russians could die fighting in Ukraine could deter the Kremlin from further military action against Ukraine, especially in light of the government's shameful efforts to hide Russian casualties from the public. This wouldn't change the course of any conflict, given the balance of forces and for this reason Russia is not likely to have a military response to such assistance; but this assistance would very likely make Russia think twice about renewed military operations.

Perhaps just as important, anti-tank missiles would demonstrate a firm as-long-as-it-take commitment to support Ukraine's territorial integrity. The Kremlin will understand that militarily, it cannot wait out Ukraine and its allies; over time, Ukraine will become stronger militarily and the military costs and risk for Russia will rise.

Only if we stick firmly with Kiev, maintaining sanctions and increasing our military assistance, will Moscow realize that time in Ukraine is also not on its side.  Perhaps then in Minsk, just as in Geneva, talks will lead to real compromise, and an opening for a united effort to destroy ISIS, al-Qaida and their affiliates.

Evelyn N. Farkas is a nonresident senior fellow at the Atlantic Council, advises companies providing military services including training, and served as deputy assistant secretary of defense for Russia/Ukraine/Eurasia from 2012 to November 2015.