A century and a half after America forced Japan to open up to the West at gunpoint, the two nations are locked in a diplomatic embrace that has some Japanese longing for freedom from the whims of the world's sole superpower.
Exactly 150 years after US Commodore Matthew Perry's "Black Ships" arrived in Tokyo Bay to persuade Japan to abandon two centuries of isolation, Tokyo is preparing to enact a law to allow its military to help US forces rebuild war-torn Iraq.
The legislation is the latest aimed at raising the profile of Japan's military and strengthening its security alliance with the US, forged after Tokyo's defeat in World War II.
But not all Japanese accept the wisdom of closer ties with Washington, which they see lurching towards unilateralism.
"It's no ordinary relationship," says Shusei Tanaka, a former cabinet minister and one-time adviser to Prime Minister Junichiro Koizumi.
"We're dealing with a country which doesn't think just about its own security, but about how it wants the world to be, and then sets its security agenda," Tanaka said.
If ties are further strengthened, "we would have to be tagging along all year long," he said.
Despite such concerns, worries over nearby North Korea's nuclear arms programs are pushing Japanese leaders to forge closer security ties with Washington.
Koizumi and his aides said Tokyo had no choice but to support Washington in the Iraq war to ensure that US forces would come to Japan's rescue should North Korea attack Tokyo.
Fear of abandonment
"We need sustained efforts to maintain the trust ... We need to strengthen the Japan-US alliance. We need to make it more `reciprocal,'" said Deputy Cabinet Secretary Shinzo Abe, one of Koizumi's top aides, after the Iraq war began.
Koizumi has taken some landmark steps to boost Japan's security role overseas at Washington's request -- despite criticism that he is eroding Japan's pacifist Constitution.
Following the September 2001 attacks on New York and Washington, Japan swiftly passed a law enabling Tokyo to provide logistical support for US forces in Afghanistan.
That reflected Tokyo's desire to avoid the embarrassment it suffered during the 1991 Gulf War when it pitched in US$11 billion but sent no troops, as well as to respond to a US request for a visible Japanese presence in the "war on terrorism."
But Tokyo's obsession with meeting US requests to "show the flag" in Afghanistan or put "boots on the ground" in Iraq also stems from a fear of being abandoned by the US.
"That's the dynamic of the past 50 years -- abandonment and entrapment," said Richard Samuels of the Massachusetts Institute of Technology, who heads the school's Japan program.
"A balance has to be struck between the fear of abandonment and the fear of being dragged into war," he said.
While "neo-conservative" lawmakers like Abe urge Japan to play a greater global security role to share America's burden, others want Tokyo to free itself from its dependent status.
Just say `No'
Younger Japanese lawmakers say that while the security alliance is vital for Japan's own protection and for regional stability, Tokyo should speak out against US unilateralism.
"I don't see Japan parting ways with the United States any time in the foreseeable future," said Seiji Maehara, a lawmaker with the main opposition Democratic Party.