On October 12 the United States and India launched an eighteen-day military exercise codenamed Yudh Abhyas (war study) in the Indian state of Uttar Pradesh. Described as "one of their largest-ever ground combat joint exercises," , the war games "involve the Indian Army Motorized Infantry Battalion and the 2nd Squadron of 14 CAV of 25 Stryker Brigade Combat Team, comprising some 320 U.S. servicemen." 
The deployment of Stryker armored combat vehicles for the drills marks the first time they have been used overseas since being introduced in Iraq in 2003 and sent to Afghanistan earlier this year. A week before the exercise began the Pentagon reported that "The Army plans to deploy 17 of its Stryker combat vehicles this month to India for the first exercise of its kind in the country.
"This is also the largest deployment of the Strykers outside of those sent to Iraq and Afghanistan." 
Far from being an isolated case, the joint U.S-Indian operation is emblematic of unprecedented military cooperation between the two nuclear nations over the past few years, in fact a strategic military partnership whose major purposes are to supplant Russia as India's decades-long main defense ally and arms supplier and to consolidate a U.S.-led military bloc in the Asia Pacific region aimed at containing China and furthering the encirclement of both that nation and Russia.
A U.S. Defense Department release on the currently ongoing exercise in question mentioned that "more than two years in the planning, [it] comes as the Defense Department continues to reach out to India to increase its military collaboration. Pacific Command's top officer, Navy Adm. Timothy J. Keating, last month traveled to India and said officials there have committed to increasing their military relationship with the United States." 
While the drills immediately address more modest goals - ostensibly practicing counterinsurgency and anti-terrorist techniques - "Hundreds of soldiers using heavy transport aircraft and battle tanks are participating in the biggest-ever war games between the two countries which were on the opposing side of the Cold War but now seek to build strategic and military ties.
"With an ally in India, Washington also seeks to keep an eye on the Chinese army's growing military mobility and strength in the area." 
In addition, an Indian press source reported that "Mid-way through Yudh Abhyas, yet another exercise named Cope India-09 between the air forces of the two countries will begin at Agra Oct 19." 
The Times of India reported on September 24 that an annual Chinese-Indian military exercise held each December since 2007 "as a major confidence-building measure between them" has been canceled for 2009.
How far the displacement of Russia as India's major military ally has progressed against the backdrop of the Pentagon's plans for an Asia Pacific analogue of NATO was detailed by the Voice of America recently:
"For decades, India mostly depended on, first, the Soviet Union and then Russia for its military supplies. But as the Cold War ended and India's relations with the United States began improving during Bill Clinton's presidency, New Delhi gradually increased its military cooperation with Washington....Today, besides holding joint military exercises with the U.S. military, India has also been buying U.S. armaments worth billions of dollars."
The same article quoted the Indian ambassador to the United States, Meera Shankar:
"Our militaries once unfamiliar with each other now hold regular dialog and joint exercises in the air and on land and sea....Our defense trade was negligible a decade ago. We placed orders worth $3.5 billion last year and it could grow even more in the future." 
Heightened full spectrum - ground, air and sea - military collaboration between the U.S. and India is in part related to the escalation of America's and NATO's war in South Asia: Afghanistan and Pakistan, India's neighbor.
On October 13 the Washington Post revealed that the White House will send 13,000 support troops to join the additional 21,000 combat forces already and soon to be deployed this year and the BBC announced the following day that "the Obama administration had already told the UK government it would soon announce a substantial increase to its military forces in Afghanistan," to be formally confirmed next week at a meeting of NATO defense chiefs in the capital of Slovakia.  On the 15th the NATO regional commander in southern Afghanistan, Major General Mart de Kruif, said of Helmand province and adjacent areas that "we need at least two additional brigades of coalition forces, somewhere between 10,000 or 15,000 troops." 
NATO's Military Committee, the senior military authority in the Alliance, just completed a tour of inspection to Afghanistan. "In attendance were Military Representatives from all 28 NATO member states as well as Military Representatives from the 14 non-NATO nations who also contribute forces to ISAF."