KUBINKA, Russia — They call it “Russia’s military Disneyland,” and the underlying idea that Russia will soon field a high-tech, modernized army was indeed part fantasy. But the bristling array of armaments underlined how military competition had overtaken diplomacy in East-West relations.

In a sprawling park 30 miles outside Moscow, President Vladimir V. Putin welcomed the country’s first high-tech military exposition on Tuesday, announcing in his opening remarks that Russia would add 40 new intercontinental ballistic missiles to its nuclear stockpile this year.

Just days earlier, it was disclosed that the United States is considering stationing enough heavy weaponry in the neighboring Baltic States and Poland to rapidly deploy some 5,000 troops to face any Russian threat.

Analysts see the increasing emphasis on military matters as a sign that the changes wrought by the Ukraine crisis are cementing a more confrontational relationship between Russia and the West, something of a new arms race.