Sunday marked the fifth anniversary of the so-called May 24 sanctions against North Korea, which the Seoul government imposed in response to the torpedoing of the Cheonan corvette in March 2010.

The sanctions banned trade and civilian exchanges between the two Koreas, new South Korean investment and non-humanitarian assistance to the North. Put simply, most cooperation and exchange programs between the two sides have been put on hold.

Given the North’s savage act and faceless refusal to admit and apologize for the sinking, which cost the lives of 46 sailors, the Seoul government had every right to impose sanctions.

The government and the ruling party also did not do anything wrong when they decided last week not to lift the May 24 sanctions, citing the lack of any change in Pyongyang’s attitude. On Sunday, the North repeated its demand that the two Koreas conduct a joint probe into the cause of the Cheonan sinking. It also insisted that the South lift the sanctions without any conditions.

The North’s recent provocations ― such as the claim of a successful test-firing of a submarine-launched ballistic missile and miniaturization of nuclear warheads ― and the brutal execution of its defense minister also suppressed talk in the South of lifting the sanctions.

But five years is a long enough time after which to take a second look at the sanctions, which not only froze cooperation and exchange between the two Koreas but also stymied overall relations between them.

What’s clear is that the sanctions have not been effective in pressuring the North Korean leadership to give up its hostility toward the South and work toward reconciliation. On the contrary, Pyongyang has increased its military threats by further building up nuclear weapons and missiles.

The May 24 sanctions have remained a major stumbling block to improving ties between the two sides. As they stand, the sanctions pose a vexing dilemma to the Park Geun-hye administration: It cannot withdraw them without due action from the North; it also cannot seek to improve bilateral ties with the sanctions in place.

The Park administration’s recent decision to allow a South Korean civilian group to ship fertilizer aid to the North ― the first of its kind since the May 24 sanctions took effect ― and authorize some other minor humanitarian assistance is seen as a move to explore some flexibility while keeping the mainstay of sanctions intact.

Obviously, any breakthrough in inter-Korean relations will not come without changes in the attitude of the North.

This is why South Korea, the United States and Japan, and the international community should make concerted efforts to use a carrot-and-stick approach to deter it from making further provocations, pressuring it to give up its nuclear and missile programs, and getting it back to the negotiating table. The fate of the May 24 sanctions should be determined in line with these efforts.

It is against this backdrop that we hope the meeting of South Korea, the U.S. and Japan’s point men on North Korea, which opens in Seoul on Tuesday, will bear fruit.