Mentor’s Comments:
This is a multilayered question. The legacy of WWII are many and the present world affairs reflect how the achievements of post WWII world affairs are on decline.

In the intro, mention the challenges that world faced after the second world war and how the new world order came into being : Integration of Europe in a single economic bloc; transformation of a bipolar world into an unipolar world with the US hegemony; various international organisations to look after the conflicts, humanitarian support and peace in the world; globalisation; nuclear race etc.

Then in the main body, mention the challenges that the world is facing in terms of the legacies and how the liberal political order of the governance is facing challenges in all major countries (Right Wing Political Parties gaining traction); how globalization is being seen not as a facilitator but as a destroyer of the economy etc. Besides these, do talk of the new challenges and trends like nuclear proliferation, aggressive china etc. Here is the hint for the topics to be discussed:
Excessive reliance on rhetorics which serve no purpose except escalating the conflict. Ex – north Korean crisis
Rising wave of protectionism (threatening economic peace) manifested in recent WTO negotiations & anti-migrant feeling. Ex- Brexit
Endangering environmental governance which in turn, is endangering the very human existence ex- US withdrawal from Paris climate agreement
Derailing peace negotiations. Ex – recent US decision to recognize Jerusalem as Israel’s capital has decimated the long & hard-earned ‘two-state solution’ to Israel-Palestine conflict
Protracted conflicts. Ex- Syrian civil war.
Lack of consensus on tackling emerging issues.
Geopolitical wars

Answer:
The second world war like the first one, started in Europe but engulfed the whole world. When the dust settled, there was destruction all around and on this debris, a new world order was created in order to learn from the mistakes of this war and make world a safer and better place. Liberalism took over in the political space and there was decolonisation of nations and integrations of various regions into singular units. UNO like international organisations were formed to maintain peace in the world. World became more open in trade and globalisation was the word of the time. But all these gains of 60 years seem in threat presently and world is witnessing challenges to these legacies of WWII.

World becoming Bipolar with aggressive China
The current international superpower dynamic is transitioning from a unipolar system with the United States as its center to a bipolar system with China occupying the other pole.
The international system is no longer characterized by a unipolar superpower with multiple great powers. Strictly economically, the world is moving toward a bipolar superpower system.

Waning Role of International Organisations
The ability of international organizations to steer world affairs is waning.
International organizations are designed to be diverse, and after World War II, they have essentially complied with the principles of the nations that were most powerful when they were formed.
But, the global power dynamic shifts toward a bipolar superpower system, these international organizations are being rendered ineffective
If leadership positions remain only in the hands of former powers, these organisations will fail to maintain international order and promote international cooperation.
When faced with a crisis, international organizations are only gathering to discuss the issue and often fail to meet the expectations of their member states.
There is a growing demand for the establishment of new international institutions that can produce practical solutions to resolve these global crises.
International organizations are thus progressing toward divergent views rather than solving practical problems.
Bretton Woods institutions, which were true post WWII legacy, are facing challenges from newly formed international organisations like AIIB, NDB, ADB.
Operations of Bretton Wood Institutions does not correspond to the formation of modern reality. In recent years, a debate has commenced regarding the effectiveness of the institutions and their role.
Therefore institutions like AIIB, NDB, ADB were formed in order to fill the gap created by the older institutions and these new institutions were more democratic in their structure and functioning.

Weakening of liberal world order:
After the Second World War, liberalism became the mainstream school of political thought internationally.
Recently, however, liberalism’s dominant position has been challenged by the principle of fairness and rise of right wing political parties.
The principles of fairness and freedom are in direct competition.
Globalization has spurred development but at the same time exacerbated the disparity between those who have and those who have not.
This is why societies, in both developed and developing countries, now demand social justice more than economic development.
As living standards rise, people have become increasingly intolerant of social injustice.
The right wing groups have seized the moment and they are pursuing the path, which nations tread before the start of WWII. Nations are becoming less tolerant of migrants and other humanitarian issues and turning themselves more inward looking. Rohingya and Syrian refugee issue are examples of this intolerance.
The Arab Spring, the Occupy movements, the European protests against austerity measures, BREXIT, increased numbers of secessionist referendums are all indications that priorities are shifting from economic development to social justice. The ideas post WW2 are waning.

Race in Nuclear Arms and rising hostility in the World:
World saw the devastating effects of atom bomb during the WWII and people thought that these types of devices will be shelved and destroyed post WWII.
But world seems to be on the brink of another great war where nuclear arms would be easily launched by any actor.
There is uncertainty on the peace initiatives on Korean peninsula and the calmness that prevailed in the US-Iran relations are waning now. India and Pakistan are already on the lowest ebb of their relationship while an assertive China is locking horns with India in various spheres. The relationship between Russia and US and its allies is on the slope and diplomatic channels with Russia has been snapped by various European nations.
Israel on the other hand is being more assertive in Middle East with increased tensions with Palestine, Iran and other Middle East nations. Middle East is already on boil with regular use of chemical weapons on innocent citizens.
This presents a grim picture because all these nations are a nuclear power and one miscalculation or wrong move can lead to a world filled with chaos and destruction and the peace which was held so tightly post WWII would slip out of our hands.

Way Forward:
The statesmanship behaviour of the leaders of that time has to be reinvented.
An attitude of tolerance, compassion & inculcation of emotional intelligence to understand other’s viewpoint. This is very important to understand ‘several emerging issues’ which are asymmetrically affecting some countries more than others.
Outright rejection of use of force to establish eternal peace. The first step in this direction can be to join recently floated total nuclear prohibition treaty.
An attitude of principled distance from intervening in every crisis militarily & inculcating the maxim that ‘reconciliation is more rewarding that retribution’
Reinvent an economic order where the judicious distribution of resources and wealth among people and nations precedes the growth numbers projected in nations’ GDP.

A world order based on liberalism, globalisation, free trade economics, peace initiatives, dialogue & diplomacy, nuclear proliferation is under attack. These were the achievements of post WWII world and countries paid a huge price to achieve them. Global community has to derive inspiration from the values enshrined in Mahatma’s talisman- take any decision after conscious deliberation of how it is going to benefit the weakest, downtrodden, underprivileged sections- such an attitude is highly crucial for resolving various humanitarian issues plaguing the world today and to restore the legacy of the post WWII world.