Rutte "is seen as a safe pair of hands to lead Nato in turbulent times, just as Stoltenberg has done for the last decade," Oana Lungescu, a former chief Nato spokesperson, said.
Although he has been one of Europe's top politicians for years, Rutte has remained down-to-earth and can often be seen riding his bicycle around his hometown of the Hague.
When he handed in his government's resignation to King Willem-Alexander last year, he drove to an ornate royal palace in a Saab 93 estate.