The world has experienced a shift away from global capitalism towards, nationalism, in the forms of new presidents such as Donald Trump. These new officials are likely to seek the betterment of their nation at the expense of others. This philosophy lead to almost every war ever. Unless your America in the cold war.
In the Eighteenth Century, the Kingdom of Great Britain had a policy to keep its Navy larger than the next two biggest Navies (which were usually the Navies of France and Spain). The purpose of this was not to encourage war, but to discourage it. Even if those two countries should combine, their Navies were still smaller than the British Navy was. This served to dissuade the enemies of Britain from declaring war upon the island Nation.
Donald Trump's plan to rebuild America's nuclear arsenal will accomplish much the same thing. No country, not even North Korea, wants a nuclear war, and certainly does not want to try and wage one with the most heavily armed nuclear power in the world. This would serve to dissuade and discourage those who would otherwise attempt to use nuclear weapons against the US and her allies.
Contrary to modern Progressive opinion, the world is not full of nice, altruistic people. We need look no further than repeated missile testing by North Korea or the acts of the Islamic State to see this fact. The world has, in fact, become more dangerous in the Twenty-First Century than it was at the end of the Twentieth. This is primarily due to the brash militancy and arrogant imbecility of the Bush administration coupled with the baseless pride and blatant cowardice of the Obama administration. The enemies of the United States, NATO, and Western Democracies see this and, until the election of Donald Trump, felt they only needed to bide their time.
Militant Nation-States like DPRK have been bullying (albeit unsuccessfully) American allies like Japan and the Republic of Korea. Rising nations like the Islamic State (which is clearly taking orders and money from some support somewhere) has made great strides in establishing itself in a destabilized region. They have also been able to follow Mao's third phase of guerrilla warfare and conduct lone-wolf attacks in both Europe and the United States. If such a power were to come into possession of a nuclear weapon, what is there to guarantee that they would not use it?
The answer is the threat of nuclear retaliation. Despite their rhetorical claims to embrace death, the Islamic State, much like the Democratic People's Republic of Korea, are led by men who wish to possess real political power. The threat of nuclear war is a threat to that power. Trump's plan certainly places nations like North Korea or the Islamic State in a position where it is highly inadvisable to use nuclear weaponry.
While Donald Trump loves to project extreme rhetoric and a supposed tough guy image, there is no chance that he will be allowed to pursue any plans that leads to a nuclear standoff with any of the other nations around the world who also possess these weapons. Those who advise him will never permit this kind of destructive behaviour as they are well aware of what the consequences could be.
Trump's call for a nuclear arms race might only be popular rhetoric. Whilst the threat of a nuclear war is ever-present, it will not likely happen because of Trump.The media of Trump as a fool who will ruin is all is completely inaccurate.Trump's power has limitations and congress would likely put a stop to events that would cause a nuclear holocaust.
During World War II, people saw the devastation that nuclear weapons can cause. Countless innocent people were killed and lives were destroyed. Even though Trump and Putin are thin-skinned, they know that the public over which they govern would never tolerate the use of nuclear weapons. People want to live in peace.
The nuclear arms race is a danger for everyone on the planet and the world leaders need to act with discipline. If we are all at risk, there should be equal measure to avoid a global disaster. Trump is not going to risk a holocaust or endanger the U.S. with irrational decisions.