It’ll be a moment of truth for NATO on Wednesday when the Western military alliance releases a joint statement on a heavily pushed and previewed collective defense spending hike.

Allies have been corralled, cajoled and pressured to hike their defense expenditure from 2% to 5% of each member nation’s gross domestic product by 2035, even as some have struggled to meet the lower target.

It’s widely expected that the bloc’s 32 member states will green light the hike on Wednesday — NATO ambassadors have already agreed in principle — but action, and the deadline, could still slip.

The U.S.′ commitment to the alliance is also in focus, after years of U.S. President Donald Trump’s frustration at Canadian and European allies not pulling their weight when it comes to defense contributions.

As he jetted into the summit late on Tuesday, Trump appeared to question NATO’s central tenet of collective defense (Article 5) that states that an attack on one member is an attack on all.