Even though these are unpleasantly exciting days in the alliance after the Ukraine crisis, many expect Stoltenberg to be an “implementation SecGen,” as the jargon has it—meaning that his main job will be to bring to life the decisions NATO made at its September 4–5 summit in Wales. There is some truth in this.

But for a successful career politician from a well-known political family, just executing what others have tasked him with seems too small an ambition. Many speculate about what agenda and leadership style Stoltenberg will bring to NATO headquarters after the visibly ambitious and at times polarizing approach of his predecessor, Anders Fogh Rasmussen.

Irrespective of the style Stoltenberg chooses, there are three top tasks the new secretary general should embrace in the coming years.

First, he needs to be exceptionally skillful in defusing the ticking credibility time bomb that NATO has created for itself. When the 28 allies announced at their summit near Cardiff that they intended to raise their defense spending to 2 percent of their respective GDPs within a decade, it was clear from the outset that this would not happen.

A small handful of NATO members are indeed inclined to get there, but the overwhelming majority—Germany among them—is not. Most countries have either said they won’t fork out on defense or stayed tellingly silent on the issue.

To be sure, the entire agreement was downgraded from “commitment” to “pledge” before the summit, so that all 28 could be brought on board. So the real (non)intentions of many NATO countries should not come as a surprise.

The problem is that allies have signed the document at the highest political level—of heads of state and government—which gives the text a political gravitas beyond its mere wording. The 2 percent goal can no longer be dismissed as just an informal political argument brought forward by a few defense hawks. It is now an official goal, and it is likely to come back to hurt NATO very soon.

The new secretary general must engage in a dual strategy: On the one hand, he must try to keep the promise, however vague it is, alive. On the other hand, he must manage expectations (which, as always, means lowering them) so that the failure to get near the spending goal does not look too much like, well, failure.

Stoltenberg could lead the campaign by presenting a plan to phase in 2 percent spending, including a time frame of the next five or ten years. That plan could then define real benchmarks not purely in terms of a percentage of GDP but in terms of tangible military assets. This way, the 2 percent goal could be redefined elegantly and brought within a more realistic reach of success.

Second, Stoltenberg needs to make himself the custodian of the readiness action plan agreed on in Wales. This elaborate project is designed to reassure the alliance’s Eastern members that NATO’s Article 5 security guarantee is more than just words on paper.

The most important component of the plan is not the high-readiness force NATO plans to set up as a response to the new “jab and pause” tactics employed by Russia—even though this element received the biggest press coverage. The real core of the project is the rotating exercise scheme that will significantly increase the nonpermanent troop presence of alliance forces in Central and Eastern Europe. The crucial task will be to keep this scheme alive over the long term.

It is true that this part of the readiness action plan is effectively established in permanence, as it would require all 28 NATO members to agree to abandon it. Yet in real terms, there is an awful lot of flexibility in the agreement, and many NATO members that came on board with clenched teeth in the heat of the Ukraine crisis may silently want to opt out as soon as that becomes politically feasible.

Other members might not even be able to fulfill their commitment because of a sheer lack of capabilities they can bring to the table. The catastrophic news of Germany’s inability to use substantial parts of its nominal military hardware because of a lack of upkeep and investment in proper maintenance should be duly noted.

This leads to the third point on Stoltenberg’s agenda. He should expect more NATO countries to declare their lack of ability to deploy even the little equipment they have. The mechanism that rendered large parts of the German air force unusable has been at play elsewhere as well. Because of the dire need to cut expenses during the euro crisis, many countries, not only Germany, put the acquisition of spare parts and expensive maintenance schemes on hold in the years after 2008. Many nations have not resumed spending.

These belt-tightening decisions are now starting to produce results in the form of grounded equipment. Many countries will be affected. One way to put pressure on member states is to make these shortcomings as transparent as possible within the alliance. This would be the secretary general’s job.

The great news is that this is a good reason for more pooling and sharing of military kit among allies. Maybe the austerity shock can give NATO’s lackluster smart defense scheme the push it needs.

There are many more things that Stoltenberg will need to do. Among them are making the nascent framework nations concept a success, reviving the suspended NATO-Russia Council (if only to make the readiness action plan transparent to the Russians), supporting Germany’s debate on the country’s changing attitude vis-à-vis hard power, and setting up a scheme to make better use of the military expertise of NATO’s top brass in the public debate.

Jens Stoltenberg is facing what will perhaps be NATO’s most crucial period of strategic positioning. It will be an incredibly busy and difficult time. But the stewardship of Europe’s prime provider of hard security is one of the most important jobs on the continent. May the new secretary general have a very skillful hand.