The Korean Peninsula is getting tense as the clouds of uncertainty gather. The United States is coming with a tit-for-tat response to tackle the provocations. The strategic options for China are decreasing, and the USS is in the process of consultation with its East Asian allies.In a recent development, North Korea launched an unsuccessful missile test on 16 April, ahead of the US Vice President Mike Pence’ visit four-nation Asia tour that includes South Korea, Japan, Australia, and Indonesia.Vice President Pence’s visit mainly surrounds the nuclear and missiles developments in North Korea. This is his first visit to the region since taking office in January. Earlier, ahead of the meeting between President Xi and President Trump in Florida on 6-7 April, President Trump had threatened to launch a unilateral strike against North Korea.Vice Present Mike Pence will assess the situation and see how its close allies, South Korea and Japan, would react. On his visit to South Korea, Pence visited the border area between the two Koreas where South Korea has a military base in the Demilitarized Zone (DMZ) at Panmunjom, with American troops stationed there and said that ”the era of strategic patience is over”. The DMZ is one of the most heavily fortified regions in the world.He also warned North Korea not to make any mistake. The National Security Advisor, Lt Gen HR McMaster, said, ”all our options are on the table to try to avoid the worst. It’s time for us to undertake all actions we can to try to resolve this peacefully.” America left the last resort to China – putting enormous pressure on it to tame its belligerent ally. This means that America will not live up with the old logic of strategic restraint and a new development is taking place.One has to see how China will put pressure on North Korea. It has suspended its air operations with North Korea since 17 April. America needs to maintain patience with China on this issue as advised by the Deputy National Adviser, K. T. McFarland. She considers that North Korea is a threat to China as well. Chinese role could preclude the need for US military action. China is pivotal – a frontline state – in the scenario. In retaliation, however, there could be a remote possibility that North Korea may militarily resort to China. Therefore, China has its own precincts to keep putting pressure on North Korea.It is not clear that if Pence’s visit is a tactical move or a warning, but no doubt it had sent an unconventional and strong message to Pyongyang that America will no longer live up with political condemnation alone. However, American legality on a possible North Korean strike would still be questionable.The sixth nuclear test by North Korea, as claimed by it, would absolutely complicate already knife-edge situation between the Pyongyang regime and Washington with no point of return as the Trump administration is taking a different course of action than all previous US administrations. The basic aim of Pence’s visits to Seoul, Tokyo, Jakarta, and Canberra is to discuss President Trump’s policy option on North Korea with the leaders of these countries and take them into confidence before America opts for a military solution. President Trump has made clear that America will no longer tolerate North Korean provocations. The response from these capitals would determine American policy of unilateral action on North Korea. Pence is building the consensus, but it should not go beyond putting maximum pressure and engagement with all stakeholders to convince the North Korean regime. The backdoor diplomacy could be fruitful, and all doors must remain opened.The writer is Director, China-Pakistan Study Centre (CPSC) at the Institute of Strategic Studies Islamabad (ISSI). He writes on East Asian affairs.