In the first half of the 1990s, I worked in Europe for The Wall Street Journal. I covered nothing but good news: the reunification of Germany, the liberation of Central Europe, the fall of the Soviet Union, the end of apartheid in South Africa, the Oslo peace process in the Middle East.
Then, towards the end of my stay, there was one seemingly anomalous episode - the break-up of Yugoslavia. In retrospect, the civil war in the Balkans was the most important event of that period.
It prefigured what has come since: the return of ethnic separatism, the rise of authoritarian populism, the retreat of liberal democracy, the elevation of a warrior ethos that reduces politics to friend/enemy, zero-sum conflicts.
In those intervening years there's been an utter transformation in the unconscious mindset within which people hold their beliefs.
Back in the 1990s, there was an unconscious abundance mindset. Democratic capitalism provides the bounty. Prejudice gradually fades away. Growth and dynamism are our friends. The abundance mindset is confident in the future, welcoming towards others. It sees win-win situations everywhere.
Today, after the financial crisis, the shrinking of the middle class, the partisan warfare, a scarcity mindset is dominant: Resources are limited. The world is dangerous. Group conflict is inevitable. It's us versus them. If they win, we're ruined. Therefore, let's stick with our tribe. The ends justify the means.
The shift in mentalities seems like a shift in philosophy. But it's really a shift from a philosophy to an anti-philosophy. The scarcity mindset is an acid that destroys every belief system it touches.
For example, in the years after Ronald Reagan, the Republican Party was defined by its abundance mindset. The key Republican narratives were capitalist narratives about dynamic entrepreneurs and America's heroic missions.
The Wall Street Journal editorial page was the most important organ of conservative opinion. The party's views on other issues, like immigration, were downstream from confidence in the abundant marketplace and the power of the American idea.
Now, Mr Donald Trump leads the Republican Party, the personification of the scarcity mindset.
Fox News, with its daily gospel of resentments, is the most important organ of conservative opinion.
Restricting immigration has become the core Republican issue. Today's Republicans are happy to trade away their fiscal principles if they can get their way on immigration, which is what they did in last week's Budget deal.
The Trump era has produced a renaissance in conservative writing. National Review is a more interesting magazine now than at any time in its history. But the style of politics that Mr Trump's scarcity mindset demands has been a disaster for conservative governance.
He insists on perpetual warfare - against all comers. Stuck fighting his wars with him, Republican politicians have had to say goodbye to most of the pillars of conservatism: rule of law, fiscal discipline, global engagement, moral decency, the idea that people should be judged by the content of their character and not the colour of their skin.
In theory, the GOP restrictionist position on immigration is perfectly legitimate. But Mr Trump has fatally entwined it with his constant race baiting. Republican politicians could have denounced the race baiting but remained silent.
They allowed themselves to become fellow travellers to bigotry, and spoiled their own cause. The fact is that the scarcity mentality and the perpetual warrior style it demands are incompatible with any civilised political creed.
At first the warriors seem to be fighting for the creed but eventually they transform it. Under the influence of this mentality, evangelicalism turns from a faith into a siege-mentality interest group.
Under the influence of this mentality, liberalism goes from a creed that values individual rights and deliberation to one that values group separatism and intellectual intolerance. The scarcity mentality always ends up eating the host philosophy because it operates on a more fundamental level of the psyche.
All of this would be survivable if the mentality was going away in a few years. But it is not going away. The underlying conditions of scarcity are only going to get worse.
Moreover, the warrior mentality builds on itself. As the right pulverises the left, the left feels the need to pulverise back, and on and on. This is a generational challenge.
Mr Trump will be succeeded by some other warrior. Eventually, conservatives will realise: If we want to preserve conservatism, we can't be in the same party as the clan warriors. Liberals will realise: If we want to preserve liberalism, we can't be in the same party as the clan warriors.
Eventually, those who cherish the democratic way of life will realise they have to make a much more radical break than any they ever imagined. When this realisation dawns, the realignment begins.
Even with all the structural barriers, we could end up with a European-style multiparty system. The scarcity mentality is eventually incompatible with the philosophies that have come down through the centuries. Decent liberals and conservatives will eventually decide they need to break from it structurally. They will realise it's time to start something new.