MUNICH — The great and the good of the Atlantic security elites, and a few of their adversaries, face an unusually complex series of challenges as they gather for their annual summit in Munich this week.

It was here, in February 2007, that President Vladimir Putin first threw down the gauntlet to the West, although his language was relatively mild by today’s standards. It has been downhill ever since: war between Russia and Georgia in August 2008; Russian aggression against Ukraine in 2014 and 2015; and now, Russian moves to undercut what little Western policy attempts there have been in Syria.

Much of the focus at the Munich Security Conference will likely be on the acute crisis that the ongoing Assad-Putin offensive has caused around Aleppo. But there is a strong need for a longer term approach to tackling the security challenge that a revisionist, nationalist and increasingly militaristic Russia poses in Europe. Three steps are essential to this end:

1. Step up support for Ukraine

According to the Minsk agreement for Eastern Ukraine, Ukraine must be allowed to regain full control over its entire Eastern border. It is important that Western pressure, including the use of sanctions, is kept up until this is the case. The issue of Crimea should be dealt with afterward.

Signs suggest that Russia is seeking to consolidate its military control over the Donbas region, and that the Kremlin wants to broker some sort of political deal with the West. Sanctions are taking their toll, but the Kremlin is prepared to stick it out, expecting reforms to fail in Kiev and calculating that the attention of Washington and Brussels — well, Berlin — will eventually turn elsewhere.

A half-baked deal that temporarily freezes the conflict today and leaves it open to flare up again tomorrow is in no one’s interest — least of all Russia’s. If the country wants a shot at the reforms it desperately needs, a true settlement in Donbas will be essential.

An international peacekeeping force, preferably with a U.N. mandate, could come in for a few years and ensure the region’s transfer back to stability within Ukraine. So far the Kremlin is strongly opposed, and places faith in its long-term destabilization efforts. But a firm Western line against half-measures could make the Kremlin change its position.

Western countries should also be ready to bolster Ukraine’s defensive capabilities in order to support the country’s political process and block military options for the Kremlin.

2. Choose deterrence over short-term reassurance in Poland and the Baltics

I fail to see any immediate risk of Russia taking aggressive action against any of these countries. They are stable democracies and solid members of both the EU and NATO. But we have a duty to look ahead a few years.

The future is increasingly uncertain, and we may well be headed toward a period of maximum danger in our relations with Russia. In 5 to 10 years, the Putin regime will face its unavoidable end, and will be considering its legacy. The country's economic and social crisis will no doubt have deepened and its perception of its military might continued to soar. If Russia sees Europe fracturing, and the West waning, temptation to act will be high.

It is important that we build up a solid defense today as a deterrent against these adventurist tendencies down the line.

The NATO Warsaw summit in July should also take further measures in this direction. Recent studies by the RAND Corporation have pointed to the need to significantly beef up the defenses of the Baltic states and Poland, including the pre-positioning of equipment for heavy army units in these areas.

Washington recently announced it would quadruple its funding for the European Reassurance Initiative, among other measures. These are steps in the right direction, but they clearly aren’t enough.

3. Create a new timetable for ballistic missile defense in Europe

Russia should certainly respect the defense concerns of its vulnerable neighbors, but that does not mean that we should be blind to Russia’s own concerns.

Although NATO, for diplomatic reasons, never said so explicitly, it was always clear that the U.S. ballistic missile defense system in Europe was about the threat from Iran. Great efforts went into demonstrating that it had nothing to do with Russia.

In his April 2009 speech in Prague, U.S. President Barack Obama confirmed the claim, saying that “if the Iranian threat is eliminated, we will have a stronger basis for security, and the driving force for missile defense in Europe will be removed.”

Iran continues to develop ballistic missiles, but with ranges geared to its more immediate region, and without nuclear warheads: The threat to Europe has been reduced. Existing and soon-to-be-completed naval systems, as well as the fixed site in Romania, can, according to studies, counter an Iranian threat far greater than exists today.

Accordingly, it makes sense to postpone the third phase of the missile defense system planned for 2018 in Poland. It serves no military need, and might well be used by Russia to leave the Intermediate-Range Nuclear Forces (INF) Treaty limiting medium-range missiles in Europe, increasing the risk of a dangerous new nuclear arms race in Europe.

The strategic landscape policymakers will discuss in Munich this year is very different from what it was a year ago — never mind five years ago.

The immediate issues that will preoccupy ministerial meetings have to be seen in a greater strategic perspective. The current meltdown in the Middle East is beginning to look like a version of Europe’s Thirty Years’ War, and will require a long-term approach — as does a militarized and revisionist Russia, which is likely to be around for years. Constitutionally, President Putin could be in office together with the U.S. president coming after the one that will be elected in November of this year.

We need to start making decisions on how to face long-term challenges with forward-thinking policies. Munich is the place to start.

Carl Bildt is a former prime minister and foreign minister of Sweden. He is co-chair of the European Council on Foreign Relations and chair of the Global Commission on Internet Governance.