President Barack Obama arrives this week in an Australia whoseeconomy is reliant on billions of dollars in mineral and energycontracts from emerging superpower China and whose security dependson an alliance with the U.S. — China's biggest rival.

Personal ties between Obama and Prime Minister Julia Gillard,born within two months of each other, underscore the nations'political bonds as China expands its security interests towardsoutheast Asia. Obama, the first black U.S. president, and Gillard,Australia's first woman prime minister, share a struggle toovercome resistance to their agendas — from universal health carein the U.S. to a mining tax in Australia.

“This relationship between Obama and Gillard has some warm,fuzzy atmospherics — their interests are congruent,” said MichaelMcKinley, a lecturer in international relations at the AustralianNational University in Canberra. “China is the elephant in the roomfor Obama and Gillard,” said McKinley, whose analysis has been usedin parliamentary testimony.

While Obama will stop at the non-commercial cities of Canberraand Darwin in a visit commemorating 60 years of postwar ties, themost recent trip by China's premier focused on business. Wen Jiabaosigned a long-term contract for A$100 billion ($101 billion) inuranium during a 2006 visit, while then-Prime Minister John Howardcame away from Shenzhen in southern China after witnessing thefirst Australian delivery of liquefied natural gas worth A$25billion over 25 years.

China has risen to become Australia's top trading partner,surpassing Japan and the U.S., which is now third, compared withsecond in 1988. Two-way trade with the U.S. has risen 4.4 percenton average in Australian Bureau of Statistics data that go back to1988, outpaced by 20 percent for the nation's commerce with China,and 16 percent for India.

By contrast, the U.S. defense relationship with Australia istightening, with Obama's visit likely to feature an agreement onenhanced security cooperation. The two sides have discussed anaccord allowing the pre-positioning of U.S. military vessels,aircraft and personnel at Australian bases and ports, a defenseofficial said in September.

“The U.S. is deeply engaged in our region and that willcontinue,” Gillard said on Nov. 12 in Honolulu, where she wasattending Asia-Pacific Economic Cooperation summit. “It's possiblefor us to have an ally in Washington and a friend in Beijing.”

Obama and Gillard, both 50, have a warm relationship,illustrated most recently when the pair passed an Australianfootball back and forth in the Oval Office during a Gillard visitto the White House in March. The president joked that she “almostbroke a bust of Lincoln.”

They visited a high school in Arlington, Virginia, where Obamaribbed Gillard in front of students about the Australian spreadVegemite, saying, “It's horrible” and told the students it was a“quasi-vegetable-byproduct paste that you smear on your toast forbreakfast. Sounds good, doesn't it?” The president said the U.S.has no stronger ally than Australia.

“They just clicked,” said Ben Rhodes, the White House deputynational security adviser. “They enjoy being around each other. Herpersonality meshes well with the president's. She's fundamentallylike the president.”

The leaders have been battling sinking poll numbers as they dealwith the backlash against unpopular domestic programs and a dimmingoutlook for the global economy. Obama's signature initiative, anoverhaul of the U.S. health-care system, is under challenge incourt and the nation's unemployment rate has been stuck at about 9percent for more than two years.

With a vote on his re-election a year away, Obama's approvalrating was 44 percent in a Washington Post/ABC News poll from Oct.31 to Nov. 3. Fifty-three percent of those polled disapproved ofthe way he's handling the presidency. It sampled 1,004 adults andhad a margin of error of plus or minus 3.5 percentage points.

While Gillard gained a victory on Nov. 8, when the governmentpassed laws to make polluters pay for their carbon emissions, herLabor Party got 32 percent support in a Newspoll survey of 1,158people from Nov. 3 to Nov. 6, against 44 percent for the oppositionLiberal-National coalition. The poll had a margin of error of plusor minus three percentage points.

A separate Herald/Nielsen poll published today showed Labor at30 percent and the coalition at 45 percent. The survey of 1,400voters was conducted Nov. 10 to Nov. 12 with a margin of error of2.6 percentage points.

Gillard's government, facing an election in 2013, isencountering opposition to its plan for a 30 percent tax on ironore and coal profits, forecast to raise A$7.7 billion in the firsttwo years should it be approved by parliament.

Hawaii-born Obama was dogged through the 2008 election andafterward by questions from some political opponents about whetherhe was born outside the U.S., and therefore constitutionallyineligible to hold the presidency.

Wales-born Gillard, who with her family migrated to the city ofAdelaide after contracting bronchial pneumonia when she was four,faces what she herself calls the nation's “blokey” culture. Thefirst Australian prime minister who isn't married, Gillard has nochildren and lives in the national capital of Canberra with herpartner, hairdresser Tim Mathieson.

A former labor lawyer, Gillard ran against an opposition leaderwho repeatedly told voters he was a supporter of “family” values ina 2010 election campaign. In one speech, Tony Abbott, leader of theLiberal-National coalition, said “the most conservative instinct ofall” is to have a family. She was shown in a 2005 Sydney MorningHerald photograph in her “eerily stark” kitchen, adorned only withan empty fruit bowl seen by some as a symbol of her life-choice asa professional.

“The opposition leader's hints at a more proper domesticposition for women say more about him than they do about the primeminister, and they do him more harm than good,” said James Clad, aformer deputy assistant secretary of defense who had responsibilityfor relations with Australia until 2009 and lived there and in NewZealand as a young man, in an e-mail.

The prime minister has signaled strong affinity with the U.S.,choking back tears during a Washington visit this year when sherecounted, during an address to Congress, her childhood feelings ofamazement upon seeing an American land on the moon. She used theimage to urge the U.S. to be bold and get back on its feeteconomically.

Obama and Gillard are dedicated sports fans. The president playsgolf on weekends and basketball on occasion, and supports theChicago White Sox baseball franchise. Gillard roots for the WesternBulldogs, a working-class team in western Melbourne that plays inthe Australian Football League, the nation's most popular spectatorsport. She is a regular at Bulldog games, where she wears theteam's red, white and blue colors.

Less than a month before she ousted former Prime Minister KevinRudd in June 2010, Gillard downplayed her then-rising popularity bysaying: “There's more chance of me becoming the full-forward forthe Dogs than there is any chance of a change in the LaborParty.”

Americans and Australians have a “similar sort of open frontierspirit” that places a “premium on individualism,” Obama said duringGillard's March visit. He visited Australia as a boy when he passedthrough Sydney from Indonesia, where he lived with his mother forfour years, during trips to visit his grandparents in Hawaii.

“The relationship is a strong one between the prime minister andObama and that will only be reinforced with the visit,” saidStephen Koukoulas, Gillard's former macroeconomic policyadviser.

Gillard's unpopularity with voters comes even as the country hadeconomic growth of 1.4 percent in the three months to June 30,fueled by China's appetite for its iron ore, coking coal and gold.That helped Australia escape a recession during the 2008-2009global economic slump.

Two-way trade between the nations in the 12 months ending Sept.30 reached A$110 billion, up 22 percent from the year before,according to the Australian Bureau of Statistics. Since overtakingJapan as the biggest buyer of Australia's iron ore in 2004, Chinanow purchases an amount of the steel-making material from Australiathat's more than four times than its Asian rival.

For the U.S., China is a source of imports, resulting in a tradedeficit with the Asian nation last year of $273 billion, while alsogenerating concern about its currency policy and strategicintentions.

“Australia is basically a Western country in Asia with a stronghistory and alliance with the U.S. and massive trade ties withChina,” said Peter Kenyon, professor of economic policy at CurtinUniversity's Graduate School of Business in Perth. Australia “canact as a conduit for ideas from the U.S. and China, and discretelyreport back to each side through diplomatic relationships.”

In Congress, the Senate adopted legislation Oct. 11 that wouldlet U.S. companies seek duties to compensate for what lawmakers sayis an undervalued Chinese currency. The measure risks stalling inthe Republican-controlled House, where Speaker John Boehner of Ohiohas called it “dangerous” and said it “poses a very severe risk ofa trade war.”

While the Obama administration has raised concerns that the billwould violate U.S. obligations under international law, thepresident yesterday said “enough's enough” on the yuan's value.China's exporters “like the system the way it is,” Obama toldreporters after a summit with Asia-Pacific leaders in Hawaii.

Security issues also are a concern. Defense Secretary LeonPanetta said in a visit to Japan last month that China is expandingits military with “a troubling lack of transparency.”

“The Americans, every now and again, let Australia know thatthey don't want to see a close strategic relationship between Chinaand Australia,” Australian National University's McKinley said.“Australia is very reliable and very useful, because it'sgeographically situated in the right place. It supports the U.S.global strategy uncritically. Australia can provide real estate fortheir military bases.”

Obama will travel to Canberra to address a joint session ofparliament, and then north to Darwin, site of the first foreignmilitary attack on Australian soil, when the Japanese bombed thecity in 1942. Announcements of major trade deals aren't expected,Kenyon said.

China bought $2.32 billion worth of uranium from Australia from2006 to 2010, according to the Department of Foreign Affairs andTrade, as part of the contract signed during Wen's April 2006visit. The natural-gas contract Howard agreed has so far reaped$166 million in sales, according to DFAT.

Obama's Nov. 17 address is likely to be less controversial thanvisits by his predecessor, George W. Bush. In October 2003, GreenParty leader Bob Brown was suspended from parliament forinterjecting during Bush's speech. Earlier that year in parliamentMark Latham, then a member of the Labor front bench and a formerclose colleague of Gillard's, called Bush “the most incompetent anddangerous president in living memory.”

Obama is in Australia to mark the 60th anniversary of thealliance between the two nations early in the Cold War. Therelationship began a decade earlier when Australia turned to theU.S. for protection against the Japanese in World War II after itsfounder and traditional ally, the U.K., which was battling Germany,failed to aid the isolated Pacific nation.

The U.S. shouldn't feel slighted by Australia's strengtheningrelationship with China, Curtin University's Kenyon said.

“The U.S. is still a very important trading partner,” he said.“Australia won't suddenly chuck out its relationship with the U.S.and throw in its lot with China. The U.S. is still the mostimportant economy in the world and it will eventually get out ofits current malaise. Australia knows that.”