(CNN)North Korea has been a threat to Japan for decades -- and it's a problem for which there is no perfect solution.
What are Japan's options against North Korea?
It's an issue important enough to have forced Japanese Prime Minister Shinzo Abe to fly to New York just days after Donald Trump won the US election last November to seek reassurance of a US-Japan defense alliance.
His concerns were not without basis -- North Korea's test missiles have regularly fallen near Japan. As recently as March 6, North Korea launched four intermediate missiles into waters off Japan, three of which landed in its Exclusive Economic Zone, and less than 200 nautical miles away from the Japanese city of Oga.
Shortly after, the city held the nation's first ever evacuation drill to prepare for future North Korean missile launches.
Meanwhile, in his visit to Tokyo on Tuesday, US Vice President Mike Pence reassured Abe that the US is "100 percent" with Japan on North Korea.
Analysts told CNN that Japanese lawmakers have discussed three options to deal with the threat -- but each of those solutions points to another problem.
Japan has relied on a US military presence for decades, but the island nation is now considering moving its Self-Defense Forces (SDF) into a more aggressive posture to help counter growing nuclear threats from North Korea.
In its 1947 post-World War II Constitution, Japan vowed to never again maintain "land, sea, or air forces or other war potential." However, in 2015, its Upper House of Parliament passed bills allowing the country's military to engage in overseas combat assignments under limited circumstances, in hopes of expanding the role of SDF to counter threats from China and North Korea.
At a parliamentary session in Tokyo last week, Abe said North Korea may have the capability to deliver missiles equipped with sarin nerve gas. Analysts say these comments are political pandering and that Abe is posturing to his domestic audience to ramp up military options.
However, Daniel Pinkston, a professor of International Relations at Troy University in Seoul, said it would be a total waste of North Korea's military assets to attack Japan. "Pyongyang doesn't care about killing Japanese civilians, especially since it would serve no military or political purpose," Pinkston said.
If Abe is willing to push the proposal forward, the opposition will try to drag its feet -- but won't be able to block it, according to Jeff Kingston, Director of Asia Studies at Temple University Japan.
"If the bill does get approved, I think China and South Korea will have allergic reactions," Kingston said. "The past is not in the past. The memories of Japan as aggressive still looms large." Kingston predicts Seoul and Beijing would lobby strongly against the bill.
Japan has its own missile defense system -- the SM-3 and the Patriot PAC-3 -- and has recently practiced a trilateral missile-threat response with the US and South Korea. But some in Japan are calling for the US to deploy the Terminal High Altitude Area Defense (THAAD) system in Japan.
Japanese Defense Minister Tomomi Inada, who has previously said Japan is considering acquiring the THAAD system, has also gone to Guam to inspect the Aegis Ashore, a land-based version of the SM-3 interceptors Japan already has mounted on its Aegis destroyers.
"I think deploying THAAD or Aegis Ashore to Japan makes a lot of sense," Adam Mount, Senior Fellow at the Center for American Progress, said. "The benefit is that it would deprive Pyongyang confidence that it could conduct limited missile strikes against Japan to try and split its opponents in a crisis."
However, a THAAD deployment to Japan would likely anger China. After THAAD was deployed to South Korea, Beijing retaliated economically by shutting down stores of Lotte, a South Korean conglomerate that offered a golf course to be repurposed for THAAD use. Chinese travel agencies stopped selling tickets to South Korea, and there have been growing calls in China to boycott South Korean products.
Experts say that while THAAD systems don't carry warheads, they carry radars that could be used to track China's own missile systems, potentially giving the US an advantage in any future confrontation with China.
"Japan and China are strategic rivals," Mike Chinoy, Senior Fellow at the US-China Institute at the University of Southern California, said. "If China is as worried as they think they are about THAAD in South Korea, they will go crazy when Japan has a THAAD system."
During his trip to Japan, Pence said diplomatic efforts on North Korea haven't worked. But analysts say Japan is not willing to encourage the US to take ill-considered action on the Korean Peninsula.
"The escalatory dynamics are just too severe for Japan, which will be right in the thick of it, given the likelihood of a clash with China taking place simultaneously," Corey Wallace, a security analyst at Freie University in Berlin, said.
Traditionally, Japan's goal has always been denuclearization of the Korean Peninsula.
"Obviously more than ever, this is an unrealistic goal, and Japanese policymakers seem to increasingly understand that DPRK is not going to give up its nuclear program," Wallace said.
Wallace says it's possible to imagine Japan grudgingly accepting some kind of limited DPRK nuclear capability if it were to develop the counter-strike capability as some lawmakers have suggested.
But the emotional trauma of North Korea's abduction of Japanese citizens in the 1970s still runs deep.
"It's very difficult for me to imagine Japan being willing to compromise by accepting a freeze in the nuclear status quo in exchange for normalization," Wallace said. "Unless DPRK comes completely clean about the whereabouts of the remaining abductees."