Throughout the 2016 campaigning cycle, then candidate Trump frequently criticized NATO as “obsolete” and repeatedly knocked allies for not paying their “fair share.”

Then, in a shocking reversal, Trump hosted a joint press conference with NATO Secretary General Stoltenberg, just a few months after moving into the White House, in which he declared: "I said it was obsolete. It's no longer obsolete."

"The Secretary General and I had a productive discussion about what more NATO could do in the fight against terrorism. I complained about that a long time ago and they made a change. And now they do fight terrorism. I said it was obsolete. It's no longer obsolete."

"(NATO) is no longer obsolete." pic.twitter.com/FwLu67097G — Salvador Hernandez (@SalHernandez) April 12, 2017

Well, it now seems he may have been right in the first instance. According to a new request for pricing (RFP) from NATO entitled, "Development of NATA Military Operations In Urban Environment Concept," NATO forces are "not sufficiently organized, trained, or equipped to comprehensively understand and execute precise operations" in modern urban environments. Here's how NATO defines their problem:

Problem statement: NATO is not sufficiently organized, trained, or equipped to comprehensively understand and execute precise operations across the maritime, cyberspace, land, air, space dimensions/domains in order to create desired effects in an emergent complex, urban littoral system possessing a dense, interconnected population.

So why the sudden interest in urban warfare? NATO's RFP conveniently cites urban population statistics from the United Nations as its justification but that's hardly a new trend so it will undoubtedly leave the cynics among us a bit skeptical.

Projections by the United Nations indicate that by the year 2035 the world population will increase to 8.7 billion people, an increase of 1.4 billion people, and that most of this growth will take place in developing countries and in urban areas. Currently 80% of the global population lives on or within 100 km of the coast; this also will likely continue. The SFA1 2013 Report – including 2015 Interim Update Report and the FFAO2 2015 have identified this trend of urbanisation as a potential instability situation for NATO. The world as a whole passed the 50% urban mark seven years ago. Estimates are that five billion people live in cities with two billion of these living in slums. It is also estimated that 1.4 million people worldwide migrate to cities each week. Studies, based upon global demographic trends, suggest that an increasing percentage of armed conflicts will likely be fought in urban surroundings.

But, irrespective of the motivation, one thing is certain...modernizing an "obsolete" international force is going to be expensive. Perhaps it's time for Trump to write up some new invoices...