But most assessments of the People's Republic of China's nuclear efforts concur, China is investing money to improve the range and mobility of its current missile systems for delivering nuclear warheads. Almost more than Russia, China expressed intense opposition to the December 2001 American decision to withdraw from the Anti-Ballistic Missile treaty and to develop a national missile defense system.

"Beijing is concerned about the survivability of its strategic deterrent against the United States and has a long-running modernization program to develop mobile, solid-propellant ICBMs (Inter-Continental Ballistic Missiles). The IC (Intelligence Community) projects that by 2015, most of China's strategic missile force will be mobile," the CIA concluded in a 2001 declassified report. "The IC has differing projections of the overall size of Chinese strategic ballistic missile forces over the next 15 years, ranging from about 75 to 100 warheads deployed primarily against the United States."

The Defense Department agreed with the CIA's assessment of the strategy behind China's investment in its nuclear arsenal in a 2003 report, saying, "Beijing probably assesses that U.S. efforts to develop missile defenses will challenge the credibility of China's nuclear deterrent and eventually be extended to protect Taiwan."

Although there is agreement that China is investing in its nuclear arsenal, scientists and journalists who track nuclear development caution against overstating China's nuclear ambitions or abilities.

"Past predictions about China's nuclear arsenal have proven highly inaccurate and exaggerated," Robert Norris and Hans Kristensen wrote in their 2003 assessment of China's nuclear forces. "In 1984, the DIA (Defense Intelligence Agency) set 'the best estimate' for the projected number of Chinese nuclear warheads at 592 in 1989 and 818 in 1994 -- approximately 50 and 100 percent above actual force levels for those years."

Best intelligence seems to peg the current Chinese nuclear stockpile at approximately 400 warheads -- roughly 250 strategic weapons and 150 smaller, tactical warheads.

		SinoDefense China is estimated to possess about 400 nuclear warheads.

The strategic warheads, all thermonuclear, are set to be delivered by missile, bomber or submarine, although the nation's bomber fleet is aging rapidly and its nuclear submarine has reportedly never left Chinese territorial waters. China's investment has instead focused on improving the mobility and reach of its missile forces.

From its outset, China has focused its program as providing a massive nuclear deterrent to any other nation -- notably the United States, Russia and, to a lesser extent, Japan -- launching an attack.

"China has chosen a strategy that is within its economic resources and suited to its geopolitical situation," a 1995 report from the Ballistic Missile Defense Organization from within the Pentagon found. "It has deployed relatively few missiles against each adversary or perceived threat. While the systems were not accurate, they were armed with large-yield nuclear warheads, aimed at major population and industrial centers, with the objective of retaliatory deterrence."

It was a policy born during one of the hottest parts of the Cold War. China hastily created its nuclear program following the outbreak of the Korean War. On Nov. 30, 1950, U.S. President Harry Truman told a press conference in Washington that the American military had considered using atomic weapons against Chinese forces if they attacked U.S. and U.N. troops pushing up the Korean peninsula.

The reaction in the international community was swift and deeply troubled. British Prime Minister Clement Attlee traveled to Washington to express his concern over the threat. In Beijing, the response was more publicly muted, but privately the Communist government implemented a crash program to develop and produce its own nuclear weapons.

China and the Soviet Union signed a technical agreement in 1950 to more closely consult one another on military matters. The treaty was a weapons and training bonanza for China, and saw the inauguration of its nuclear weapons program. By 1957, a second agreement had been reached to deliver a complete atomic bomb design to the Chinese.

But then relations between the two communist nations began to sour. By June 1959, the Soviets scrapped plans to deliver the weapons design and by 1960 all Soviet technical advisers had left the country. China now needed to finish its bomb on its own.

"Since its inception, China's nuclear weapon program has relied on a mixture of foreign assistance, indigenous know-how and espionage to steadily develop and modernize its nuclear arsenal from its first implosion device to the development of tactical nuclear weapons in the 1980s," the Nuclear Threat Initiative reported.

It was this indigenous know-how that produced the country's first atomic weapon in 1964. The device, called 59-6 for the year and month the Soviets had ended their assistance to the Chinese effort, heralded a swift series of nuclear developments for the People's Republic.

		Peoples Army Archive China developed its first thermonuclear bomb in 1967.

Less than a year later, the Chinese tested their first air-dropped bomb, meaning they now had a workable weapon design. By 1967, less than three years after going nuclear, China detonated its first thermonuclear weapon -- a massive bomb that packed more than a 3-megaton punch.

The '67 blast meant China had achieved in just 32 months what took the Americans 86 months, the Soviets 75, the British 66 and the French some 105 months.

Given its limited economic resources to devote to the weapons program and its strategic decision to only target enough large thermonuclear weapons to ensure massive destruction, China stopped large-scale production of nuclear warheads in the early 1980s with a stockpile of 400 warheads.

The PRC has continued to develop its rocket technology and has focused on making its current stockpile of warheads more mobile and lighter in hopes of being able to defeat any U.S. national missile defense shields.

-- Compiled by Lee Banville for the Online NewsHour