This Pentagon map shows what's really driving China's military and diplomatic strategy

China leaders believe their country is a rising superpower on track to have the world's largest economy and Asia's most formidable military.

There's one huge problem: energy needs.

Hopes for energy independence have been dashed by China's continuing population growth, along with increasing per capita consumption as the economy expands.

Continued economic growth is imperative for China's leaders. The Communist Party's legitimacy, and the social and political stability resulting from it, is largely dependent on rising prosperity. China's oppressive political system is generally tolerated (although beloved) because of the growth its brought the country.

That implicit arrangement can't last unless the Communist Party upholds its end of the deal and keeps growth going. But an industrialized and still developing economy like China's can't grow without plentiful oil and gas.

In order to offset rising demand and ensure both economic growth and its own long-term survival, China's Communist Party-led government has "constructed or invested in energy projects in more than 50 countries," the Department of Defense's 2015 report on the Chinese military notes. This has enabled China to import approximately 60 percent of its oil supply in 2014 as well as about 32% of its natural gas supply.

This reliance on energy imports puts Beijing in a potentially uncomfortably position, as a map in the Pentagon report demonstrates. Oil and gas imports are a life-and-death matter for China's rulers, meaning they need a military strategy to defend crucial energy chokepoints.

As the map shows, large percentages of China's petroleum move through two of the world's main maritime chokepoints (note that the percentages shown add up to over 100% as shipments may travel through multiple chokepoints):

According to the Pentagon report, China imports at least 51% of its oil from the Middle East. Approximately 43% of this oil has to pass through the Strait of Hormuz while 82% of all Chinese maritime oil imports must pass through the Strait of Malacca.

Both of these chokepoints are vital to global maritime traffic and susceptible to potential conflict. In the midst of the 1980s Iran-Iraq War, Iran essentially closed off the Strait of Hormuz against any maritime traffic it considered suspicious, which lead to a brief US military engagement with Tehran in Persian Gulf. The Iranian navy harassed two foreign-flagged vessels in the Strait in April, including a US-flagged ship.

Meanwhile, the Strait of Malacca has become a global piracy hotspot. With 82% of its maritime oil imports and 30% of its maritime natural gas imports passing through here, Beijing is eager to develop more reliable alternate routes for energy imports. This may be an especially urgent need around the Strait of Malacca, which opens into the increasingly tense South China Sea.

In order to alleviate its reliance on oil and gas that passes through these chokepoints, China has undertaken construction of a number of new pipelines. A Russia-China pipeline will double capacity from 300,000 to 600,000 barrels of oil per day by 2016, as the Pentagon map shows.

China has also nearly completed a pipeline from the Burmese port of Kyuakpya to the Chinese city of Kunming. The pipeline, which allows ships to bypass the Strait of Malacca, will carry 440,000 barrels of oil per day from the Middle East and Africa.

Beijing's foreign policy strategy has been oriented around establishing access to energy-rich areas. Policies like the multi-billion-dollar "New Silk Road" trade initiative, the construction of a "String of Pearls" consisting of ports and naval bases ringing the Indian Ocean, and efforts to establish a military foothold in disputed sections of the resource-rich South China Sea are all aimed at keeping the oil and gas flowing well into the future.

That's also the goal of recent Chinese diplomatic outreach, like Chinese Premier Xi Jinping's high-profile meetings with the leaders of Pakistan and Russia over the past month. Beijing's naval aspirations, which include the construction of additional aircraft carrier groups, are meant to project Chinese hard power into the navigation routes most important to the country's energy trade.

The Pentagon map shows how dependent China is on these imports - and how that's driving Beijing's sometimes-aggressive engagement in its region and hte broader world.