WASHINGTON (WASHINGTON POST) - It has become the ultimate symbol of American resolve against the threat of North Korea: a visit by the US commander in chief to "freedom's frontier", the heavily guarded demilitarised zone (DMZ) that has separated the North and South for 64 years.
Wearing bomber-style jackets, surrounded by military officers, peering through binoculars, all but one president since Mr Ronald Reagan has gazed across the barren strip of land at the 38th parallel from an observation post - and been moved to talk tough.
In April, Vice-President Mike Pence, undertaking the same solemn ritual, said he toured the DMZ so the North Koreans could "see our resolve in my face".
But as President Donald Trump prepares for a 12-day swing next month (November) through five Asian nations to bolster international pressure on Pyongyang, the administration is divided over whether he should make the pilgrimage, an issue that remains unresolved.
Some aides worry that a visit could further inflame already heightened tensions on the Korean Peninsula, while others have expressed concern over Mr Trump's personal safety, according to people who have spoken to administration officials.
Asian foreign policy veterans of both the Barack Obama and George W. Bush administrations said it would be foolish for Mr Trump not to go.
But the White House is facing opposition from South Korean President Moon Jae In's administration and the US State Department over fears that a visit would ratchet up Mr Trump's war of words with North Korean leader Kim Jong Un.
A White House spokesman declined to comment, saying the administration was not ready to release the full itinerary for Mr Trump's trip, which is scheduled to last from Nov 3 to Nov 14.
Asked during a news conference this week whether a DMZ visit would provoke Pyongyang, Mr Trump said the trip's details were not finalised and added: "I didn't hear in terms of provoking, but we will certainly take a look at that."
Mr Trump has already done plenty of provoking amid reports that North Korea's ballistic missile and nuclear weapons programmes are making more rapid advances than expected. Mr Trump has repeatedly mocked Mr Kim as "Little Rocket Man", and he declared during a United Nations speech last month that the United States is prepared to "totally destroy" the North if necessary.
Mr Kim has responded with his own harsh rhetoric, calling Mr Trump a "mentally deranged US dotard", and by threatening to strike Guam and test a nuclear device over the Pacific Ocean.
Mr Trump will have plenty of other chances to talk tough, starting with a tour of the Pearl Harbor military base in Hawaii on his way to Asia.
In Tokyo, the president is scheduled to meet with the parents of a Japanese girl kidnapped by North Korean agents four decades ago, and in Seoul, he will deliver a speech to the South Korean national assembly.
But current and former US officials said a presidential visit to the DMZ sends a more pointed message to the American and South Korean troops who patrol the border region just 30 miles north of Seoul - as well as the enemies forces on the other side - that the United States remains committed to the bilateral defence treaty that has been in place since the armistice that halted fighting in the Korean War in 1953.
"The DMZ functions as a kind of amplifier," said Mr Daniel Russel, who served as assistant secretary of state of East Asian and Pacific affairs under president Obama and is now a senior fellow at the Asia Society. "The message takes on a more martial and ominous tone when it comes out of a military command post on North Korea's doorstep."
Mr George H.W. Bush is the only president since Mr Reagan toured the DMZ in 1983 not to visit, although Mr Bush did make his own trip while serving as Mr Reagan's vice-president.
Mr Obama visited the DMZ during a 2012 trip to Seoul for a nuclear summit, telling the troops that "the contrast between South Korea and North Korea could not be clearer, could not be starker, both in terms of freedom but also in terms of prosperity".
In 1993, president Bill Clinton told reporters during a DMZ tour that if the North ever used nuclear weapons "it would be the end of their country".
Mr Clinton walked so far across the Bridge of No Return that joins the two Koreas that US Secret Service agents reportedly brought rifles into the area to protect him, in violation of the Korean War ceasefire.
Officials in Seoul and Tokyo are eager for Mr Trump to reaffirm his commitment to the US defence treaties with its East Asian allies. The president has unsettled Mr Moon and Japanese Prime Minister Shinzo Abe by criticising US trade imbalances with those nations, pulling out of a 12-nation Asia Pacific trade accord and demanding a renegotiation of a bilateral trade pact with South Korea that Mr Obama signed in 2011.
At the same time, Mr Moon's advisers fear that a Trump visit to the DMZ could increase the chances of a miscalculation that could provoke a military confrontation or have other unintended consequences, such as harming Asian financial markets or disrupting planning for the Winter Olympics, which will be held in PyeongChang in February.
Mr Evan Medeiros, who served as senior Asia director at the National Security Council under Mr Obama, said Mr Trump "needs to be crystal clear" over the US position on North Korea and suggested that the costs of not visiting the DMZ could be greater than going.
"If he doesn't go, guess what the next story is?" said Mr Medeiros, who accompanied vice-president Joe Biden to the DMZ in 2013.
Already, some foreign policy experts are mocking the White House's hesitation.
On Tuesday, Mr Jeffrey Lewis, a nuclear non-proliferation expert who operates a popular Twitter account, included a chicken emoji with his retweet of a South Korean news report that US and South Korean officials were steering Mr Trump away from the DMZ.
Former US officials emphasised that Mr Trump's national security team could craft a visit that achieves the symbolic message - speaking to the troops, touring Observation Post Ouellette - without directly provoking the North with hostile words.
But they acknowledged that the president, who would be accompanied by reporters, is prone to straying off message.