Sweden is leading the major military exercise Aurora 17 in September, with units from all over Sweden, at sea, land and air. More than 19,000 troops are set to take part, including 1,435 soldiers from the US, 270 from Finland, 120 from France and between 40-60 each from Denmark, Norway, Lithuania and Estonia.
It will focus on the Stockholm and Gothenburg regions and Gotland, the Baltic Sea island at the centre of military discussions in Sweden, where fear of an increasingly assertive Russia has grown in recent years.
"Aurora 17 is the first and biggest exercise of its kind in more than 20 years," said Sweden's Armed Forces.
Lieutenant General Ben Hodges, the commanding general of the US Army forces in Europe, described Gotland as a key location on a visit to the island ahead of the exercise.
"I look forward to my soldiers being given the opportunity to train as much as they can with you," newspaper Dagens Nyheter (DN) quoted him as telling Swedish troops permanently stationed on the island for the first time since 2005.
"You have a strategically very important task here. I do not think there is any island anywhere that is more important."
Non-Nato member Sweden has strengthened its ties with the military alliance in recent years, despite Russia's words of warning that an expanding Nato would be seen as a "threat".
Russia will hold a joint exercise, Zapad 2017, with Belarus around the same time as Aurora 17, seen by many Nato allies as an attempt to flex its muscles. The US has also stepped up its presence in eastern Europe with troops and tanks as part of a Nato military build-up that has drawn criticism from Moscow.
"Russia has changed the security environment," Hodges told DN.
"We have to react to that, and not just the US, but the whole of Nato. The countries closest to the bear have historical experience. They feel the hot breath of the bear – and they are the ones most worried."
"The fact that Sweden decided that they have to put troops back on Gotland is a very clear indication of what's going on. Sweden is known as moderate, credible and alliance free. Nevertheless Sweden felt that this was necessary."
Ben Hodges' comments in Dagens Nyheter were translated from Swedish to English by The Local. We understand his original comments were given in English, translated to Swedish by Dagens Nyheter.