When the US earmarked billions of dollars for a new national missile defense and broke ground in Alaska, Washington emphasized that it would be "no threat to Russia."
Then, with the inevitability of a cold-war counterpunch, President Vladimir Putin saw fit to reassure Russians that America's shield could be defeated, with a silver bullet successfully tested in February.
"No country in the world as yet has such arms," Putin declared of the new weapon, which amounts to a space cruise missile. It will be "capable of hitting targets continents away with hypersonic speed, high precision, and the ability of wide maneuver."
Welcome back to the future of US-Russian rivalry. Analysts say that a combination of US military efforts - including missile defense, plans for new low-yield nuclear weapons, and expansion up to Russia's western doorstep - are chilling relations with Moscow and spurring a new, higher-tech arms race.
Despite American declarations of goodwill, Russian interpretations of US military shifts are tangled up with a deep history of rivalry, and a current fear of being left behind. A strategy rethink is under way in Moscow. Senior officers speak of an "asymmetrical" response to counter US strength without matching Washington's expenditures.
"I understand America's measures as a continuation of the arms race," says Viktor Baranets, military columnist for the Komsomolskaya Pravda newspaper. "With our slim budget we are making an effort to catch up with the rich American chariot."
"They think that we're kind of crazy to be pursuing [missile defense]," says Marshall Goldman, of the Davis Center for Russian Studies at Harvard. "It is just another example in their minds of how the US is still fighting the cold war."
And missile defense is not the only issue.
Work by the US on new types of nuclear weapons helped prompt the largest Russian military exercises since the Soviet era earlier this year. Russia is especially alert to the "possible reemergence of nuclear weapons as a real military instrument," which it views as an "extremely dangerous tendency that is undermining global and regional stability," Defense Minister Sergei Ivanov wrote in the journal Russia in Global Politics. "Even a minor reduction in the threshold for the use of nuclear weapons would require Russia to revise ... the use of its units."
Mr. Ivanov also warned in March that if "anti-Russian elements" persist in any NATO "offensive military doctrine, Russia will have to adequately revise its military planning ... including its nuclear forces." In April, four Belgian F-16 fighter jets deployed to Lithuania to patrol the alliance's new shared border with Russia. The move prompted sharp criticism from Moscow of an imminent "collision."
Moscow is also trying to figure out how to at least keep up with America's growing military resources. In recent years, Russia has moved to extend the service life of its multiwarhead SS-18 and SS-19 intercontinental ballistic missiles (ICBMs), and purchased 30 like-new SS-19s from Ukraine. Last year, Putin said of newly deployed SS-19s: "Their combat potential, including penetrating through any missile defense, is without peer."
Though these ICBMs are a critical component of Russia's strategic nuclear forces, they don't always work. Test launches in February, intended to be the highlight of Russia's intense military exercises failed, despite the presence of Mr. Putin - smartly attired in Naval uniform - on the deck of a nearby submarine.
To the acute embarrassment of the Russian General Staff, two sub-launched missiles never left their launch tubes. A third ICBM, fired the next day, veered off course after 98 seconds of flight and self-destructed.
However, Putin's new "secret" weapon can ride atop the relatively new, three-stage SS-27 missile, known as the Topol-M. Experts say the weapon is a maneuverable warhead that can dart unpredictably at high speeds as it reenters the atmosphere, making it virtually impossible to target at that stage. It is essentially a space cruise missile, born from Soviet efforts to penetrate Ronald Reagan's "Star Wars" missile shield, which was never built.
"It's hard to tell if [the breakthrough] would have been possible without [concern for US] missile defense," says Pavel Podvig at the Moscow Institute of Physics and Technology. "Missile defense has no real military value ... but at the same time, it has very serious political value. Missile defense is not such a serious issue that it drives us back into the cold war, but it makes dismantling that system much more difficult."
Russian unease may also erode support for Washington's war on terror.
"It might lead to our relations becoming cooler instead of united in our effort to oppose common threats from terrorism," says columnist Baranets. "Should [the US and Russia] go on building more warplanes, missiles, and subs just because our brains haven't been cleaned from the cold war dirt? Or should we jointly protect ourselves from stones somebody might throw [our way]?"
Still, since Sept. 11, 2001, Russia cast itself as a fellow terror fighter, side by side with Washington. But Russia did staunchly oppose Washington's withdrawal from the Anti-Ballistic Missile (ABM) treaty in June 2002. The treaty forbade deployment of a missile defense network. The US has since began work in Alaska for an initial 10 interceptor missiles, meant to stop a single missile from a "rogue" state like North Korea.
"It's US taxpayers' money, so if they want to waste it, Russia should not involve herself explaining to Americans why [missile defense] is not worth it," says Vladimir Orlov, director of the Center for Policy Studies in Moscow.
Indeed, the controversies in the US that are swirling around the system have not gone unnoticed in Russia. Though a limited system is due to go online later this year, the Pentagon's top weapons tester told Congress in March that operational testing was not planned "for the foreseeable future," and that he could not be sure the system would work against a North Korean missile.
The General Accounting Office has found that only two of 10 key technologies for the system have so far proven to be workable. In light of that - and far greater concern about terrorism - 49 retired US generals and admirals wrote to President Bush in late March suggesting delaying deployment.
"The Russian military and scientists understand that [US missile defense] is a joke, but that doesn't mean that everybody understands that - it's a political environment," says Theodore Postol, a physicist at the Massachusetts Institute of Technology.
"If I wave a plastic gun in front of the police, when they are nervous and they think I'm a terrorist, I'm going to get shot, though the gun has no capability," adds Mr. Postol. "That's the game the Bush administration has been playing, with extremely negative consequences for the US."
Some here quietly welcome those consequences. "Russia is thinking: Should it really oppose [new US weapons], or use them as an excuse to follow the same path?" says Ivan Safranchuk, head of the Moscow office of the Center for Defense Information.
For Russia's long-neglected defense industry, the US moves are a potential boon.
"This gives the bombmakers an ... opportunity to revive programs that were actively pursued in the 1980s," says Pavel Felgenhauer, an independent defense analyst in Moscow. He says top Russian officials told him several years ago that plans had already been made "to resume [nuclear] testing, as soon as the Americans give the go ahead ... so that it will be their fault, not ours."
Already, there are signs that Russia reacted offensively to US missile defense plans before they even left the drawing board. Russia launched a 2002 exercise that simulated an attack on Moscow ABM system, which experts say mirrored a strike on a future US system.
"We know from history that people react, nations react, and I would expect Russia to gin up its nuclear weapon R&D programs in response," says David Albright, head of the Institute for Science and International Security in Washington.
Indeed, military historians point to the example of the missile defense system deployed around Moscow in the late 1960s - and the exaggerated American response, which boosted the US nuclear stockpile - as a case in point.
According to a recent detailed analysis in the Bulletin of the Atomic Scientists, the CIA in 1967 estimated that Moscow's nonhardened system was "subject to saturation and exhaustion." Still, it was targeted with missiles from Polaris submarines and more than 100 Minuteman ICBMs - some 10 percent of all of the US ICBM force. The result was a "staggering average of eight 1-megaton warheads per interceptor launch site" with a combined force exceeding 7,500 Hiroshima bombs. Such "chilling examples ... fundamentally contradict the portrayal of missile defenses as nonoffensive" concludes the Bulletin.
Such hypersensitivity seemed to disappear in the post-Soviet 1990s, an era of anything-goes US-Russia contacts and joint efforts to safeguard nuclear stockpiles. But there are signs of renewed suspicion.
Russia's secret cities, where much nuclear and other hidden military work took place, are again clamping down. Several military experts have been charged and jailed for allegedly giving away state secrets.
Even military exchanges have chilled. For example, a Harvard program for Russian officers to learn about civilian control of the military notices the change.
"When the Ukrainians and other East Europeans [take part], back home it is considered a leg up on their career path," says Harvard's Goldman, while Russians, these days, are beginning to feel the opposite. "They've been compromised if they come, because they've been consorting with the enemy."