At times like these it seems appropriate to reflect on the state both of Europe and the world. There’s little doubt that the European order, indeed the global order, that we’ve been trying to shape is changing in profound ways.

We nowadays see the outbreak of the Great War as the true beginning of the “horrible” 20th century, with all the horrors of the trenches, revolutions, depressions and dictatorships, and then the gas chambers, concentration camps, barbed wire and walls that followed.

It wasn’t until a mere quarter-century ago, with the elections in Poland and the fall of the Berlin Wall, that our continent was able to start rebuilding its future and that we could dare to start dreaming of a Europe that would be whole and free, democratic and dynamic.

The years since then have seen some very major achievements. And looked at globally, they have been among the best of times for mankind as a whole. What Europe achieved during these few decades was an important part of the international success story.

“We must understand that, in contrast to our obviously misjudged reactions after the August 2008 war between Georgia and Russia, the Ukraine crisis is more than an unfortunate episode that will soon pass”

Few people predicted Germany’s peaceful reunification, and fewer still the re-establishment of the three Baltic states’ independence. But we also saw the setbacks of a brutal decade of war in the Balkans that were a horrendous echo of a century before.

Major wars in Europe’s history normally ended with major peace settlements that sought to regulate matters in a way that would secure peace and stability in the years ahead. That’s why we think of the Peace of Westphalia of 1648, the Treaty of Utrecht in 1713 or the Vienna Congress in 1815. And then, of course, there was Versailles in 1919, whose legacy left so much to be desired. It is hardly surprising that it’s so often referred to as “the peace that ended all peace”.

It wasn’t until a quarter of a century ago that national leaders could sit down and seek true agreement on the principles for peace for our continent after all the horrors that stemmed from that fateful summer’s day of 1914 in Sarajevo.

That’s what they did as they set down exactly such principles in the Paris Charter of 1990, and as a result laid down later in the ambitious concept of the Organisation for Security and Co-operation in Europe.

“If Russia’s actions were to be accepted, we could well see a situation arising where, over time, the solidarity on which the European Union itself is built comes under strain, with all the unpredictable developments that might involve further down the line”

What was spelled out at that time was a concept of peace that went far beyond defining an absence of war. It defined peace built on respect for human rights for each and every person in our societies. We Europeans learned the lesson of the 20th century’s bitter experience, which was that the internal order of a state is as relevant to peace as the relationships that exist between them.

It was therefore very important that membership of the Council of Europe and of the European Court of Human Rights should be extended to all the nations of our continent.

Much of this was, of course, about Russia. It was of paramount importance that we should devise an order that included both Russia and the other states that emerged from the collapse of the Soviet Union. A first step was the Partnership and Co-operation Agreement concluded in 1994 between the European Union and Russia, and in 1997 this was followed by the Founding Act signed by NATO and Russia.

The Soviet Union might have lost the Cold War, but the new Russia that emerged was very much a part of the shaping of the new order of peace and security that followed. There was never – and in view of subsequent developments this is a very important point – any talk of Versailles-style humiliations. The new Russian Federation with its democratic and European aspirations throughout the 1990s was embraced positively by Europe and by the West as a whole.

Some key principles were embodied in the various arrangements concluded during those formative years, and naturally they reflected the experiences of the bitter decades that had gone before. They also owed something to the challenges presented by the break-up of first the Soviet Union, and then of Yugoslavia.

“It seems most unlikely that Russia’s revisionism would end with Crimea or the mainly Russian-speaking Donbass region of Eastern Ukraine”

The Belavezha Accords of December 1991 that ended the Soviet Union yielded agreement that all of the USSR’s constituent republics would have the right to independence, but that independence would be contained within their existing borders. And at the start of the Yugoslav crisis, the so-called Badinter Commission set up by the then European Community laid down that same principle.

Belavezha and Badinter thus said the same thing: yes to independence and self-determination, but borders must be respected, and any change in them would have to be agreed upon.

There were very sound reasons for this. National borders within Europe have more or less all been drawn in blood over centuries of brutal conflict, ethnic cleansing and mass movements of populations. Sometimes these borders still seem logical enough to the modern eye, but there are also cases – many of them in the former Soviet Union and the Balkans – where this is more questionable. But to open up those cases, or to invite others to do so, would be to risk blood flowing once more.

The principle of respecting existing borders and boundaries was thus laid down among the key foundations for peace in Europe, and until March of last year was strictly adhered to.

Throughout the years of Balkan conflict, we in Europe refused to accept any changes to what had been the boundaries within the Republic of Yugoslavia. We insisted on the territorial integrity of Croatia and refused to contemplate the dissolution of Bosnia, we defended the integrity of Macedonia and were clear that northern Kosovo should remain northern Kosovo and that southern Serbia should remain southern Serbia.

“We should also recognise that it will no longer be enough just to issue declarations and hope that a diplomatic dialogue will smooth things over – even if it fails to sort them out”

The decade of war that engulfed the Balkans from Slovenia to Macedonia was brutal and horrible, yet I’m truly convinced that the violence would have been far worse had we not stuck to this principle.

We should remember, too, that we also respected this principle when it came to developments in Russia itself. Although we were often horrified by the conduct of Russian forces as they tried to put down Chechen calls for self-determination, and although we were harshly critical of the massive human rights violations that followed, we never wavered in our support for the territorial integrity of the Russian Federation.

So it was natural that we should remain faithful to this principle when war came anew to the southern Caucasus in August 2008. The territorial integrity of Georgia was seen as being as important as the territorial integrity of Russia. In this way, we in Europe resoundingly refuted the historic practice of changing borders through force. We embarked more determinedly than ever on the building of Europe through the peaceful shrinkage of the importance of borders.

Our policies in this respect were never limited only to members of the European Union. Our vision of a Europe of free movement of goods, services, capital, people and ideas from Lisbon to Vladivostok still remains, and its building blocks are there for all to see.

The EU’s Eastern Partnership for Ukraine and for the five other countries that lie in between ourselves and the Russian Federation is among these important building blocks. The accession negotiations with Turkey constitute another, with the EU’s Thessaloniki commitment to all the countries of the Western Balkans holding up yet one more. The talks that have taken place since 2008, and aim at what’s called a New Agreement with Russia to replace the old Partnership and Association Agreement, also reflects much the same ambition.

Since the start of 2014, though, we have been faced with a new situation, and it’s one in which our principles and our vision are being fundamentally challenged. They say the 20th century started in 1914, and future historians may well say that the 21st century started in 2014. In the early hours of Wednesday February 27 an armed group seized control of the Crimean parliament building in Simferopol, and in a few ensuing hours the old leadership of the autonomous region was thrown out while a new one with a very different programme was installed.

It took some time until we in Europe realised what we now know for a fact: these were special forces of the Russian Federation, but operating without national insignia. The invasion, occupation and annexation of Crimea that followed wasn’t just a smash-and-grab operation of limited importance and relevance. It was a fundamental violation of the core principles of security of Europe that had been agreed following the end of the Cold War. Since then, Russia has been trying to advance a number of different arguments to justify what it did. None of these can be accepted, however, without grave consequences for all of our futures.

In Moscow, the Kremlin has certainly had its disagreements with Kiev, and was horrified when Ukraine’s then President Viktor Yanukovich simply abandoned his post, and the February 21 agreement led it to fear that a new democratic spirit was emerging there. However strongly the Kremlin may have felt about these developments, dislike of whatever is happening in a neighbouring country can never justify an invasion of it.

The chief argument put forward by Russians, and not least by President Putin himself, has been that Crimea was part of Russia and was handed over to Ukraine only in 1956. In fact, Crimea’s very long and rich history has brought it under a number of empires and their rulers, and only for less than two centuries was the peninsula an integral part of Russia. A quick look at the map of Europe is enough to remind us that there are few places that have not at some time been part of another state, and in many cases for far longer than two centuries. The three Baltic states, for example, were part of Russia for longer than the Crimea.

It may well be true that a substantial portion of Crimea’s Russian-speakers thought its inclusion within Russia to be a good idea, even if opinion polls before the invasion had not shown significant support for this. But if their acceptance of the annexation amounts to a justification, the same logic can be applied by various other nationalities in other parts of Europe. In the Balkans, for instance, you could easily organise similar so-called referendums that would yield dramatic upsets for some states in the region.

In other words, there are profound dangers inherent in the arguments put forward to justify the Russian invasion, occupation and annexation of Crimea. We in Europe are confronted with an attempt not only to revise borders, but also the key principles that underlie our security.

The threat to these principles has been made clear in a number of other ways. President Putin’s Kremlin speech in March of last year following the annexation of Crimea set out his ‘Greater Russia’ vision, and in a way built on the concept he had put forward after Russia’s brief war with Georgia in August 2008. This expressed his views of Russia’s right to use armed force to protect its citizens in neighbouring countries. Since then, he has gone even further, for at the Valdai conference in October of last year he made a speech entitled “New Rules, or a Game with No Rules” in which he explicitly said that under his leadership Russia no longer accepts existing rules on the inviolability of national borders. He proclaimed that as a first principle “changes in the world order – and what we are seeing today are events on this scale – have usually been accompanied, if not by global war and conflict, then by chains of intensive local-level conflicts.”

Although it was said implicitly, not explicitly, the invasion of Crimea and later efforts to dismember Ukraine by setting up the so-called Novorossia entity should be seen as concrete applications of this principle. Russia’s Deputy Prime Minister Dmitry Rogozin has tweeted that what we are now seeing is the restoration of Russian power, and that confrontation with the West must be accepted as part of this process.

These revisionist messages would seem aimed at returning to the concept of ‘spheres of interest’ that entail limited sovereignty for some, and limitless rights for others. It is a world where might is right, and were the law doesn’t apply equally to all.

If we Europeans were to accept this, the consequences would be profound. This is especially true of eastern Europe, for if we accept that Russia has the right to place limits on Ukraine’s sovereignty, what guarantee is there that it would not seek to exercise the same right elsewhere? It seems most unlikely that Russia’s revisionism would end with Crimea or the mainly Russian-speaking Donbass region of Eastern Ukraine.

“Today, we begin to hear once again the thunder of the guns, and it is not only the revisionist Russian power to the east that is the challenge. To Europe’s south we see a risk that the Middle East as we used to know it is unravelling”

The consequences risk going even wider. If Russia’s actions were to be accepted, we could well see a situation arising where, over time, the solidarity on which the European Union itself is built comes under strain, with all the unpredictable developments that might involve further down the line. We can already see political actions in some EU countries expressing admiration for Putin as a strong man who is unafraid to resort to military might, and whose ‘macho-nationalism’ seeks to dictate the fate of others. The deeply disturbing fact is that a number of countries around the world now seem ready to look the other way, and so avoid taking a stand on the Ukraine issue.

This ambivalence does not stem primarily from any particular sympathy with what Russia has done. But some might see opportunities for the future, whether it be a quick land grab, the settling of old scores or just asserting some right they may consider theirs. There are a good many parts of East Asia where this could happen, and where the consequences would be extremely dangerous. Central Asia is, after all, a region where instead of being logical, borders were often arbitrarily drawn by the old Soviet powers.

The implications of Crimea’s annexation thus go well beyond Ukraine, and even beyond Europe, for these implications challenge the rules of the international order. That’s why it is of the utmost importance that we should be ready to stand up together against these developments. We in the EU must never appease aggression, and we must never surrender our principles.

We should also recognise that it will no longer be enough just to issue declarations and hope that a diplomatic dialogue will smooth things over – even if it fails to sort them out. We must understand that, in contrast to our obviously misjudged reactions after the August 2008 war between Georgia and Russia, the Ukraine crisis is more than an unfortunate episode that will soon pass.

A policy experts’ report to the Secretary General of NATO in the run-up to the alliance’s Newport summit in Wales last September looked at the wider picture and concluded that “the emergence of a more dangerous world in the second decade of the 21st century poses a historic test for the governments of the transatlantic community.” And we have certainly come a very long way from the triumphalist introduction to the European Security Strategy of 2003, which said that “Europe has never been so prosperous, so secure nor so free” and that “the violence of the first half of the 20th Century has given way to a period of peace and stability unprecedented in European history”.

Today, we begin to hear once again the thunder of the guns, and it is not only the revisionist Russian power to the east that is the challenge. To Europe’s south we see a risk that the Middle East as we used to know it is unravelling. In a report back in 2006, the Paris-based EU Institute for Security Studies warned of “the possibility of a systematic break-down of the entire Middle East”. Almost a decade later, large parts of that region seem to be heading for an Arab version of the Thirty Years War that divided Europe half a millennium ago.

Growing instability in the EU’s immediate neighbourhood is affecting us more and more. For some years, units of the Swedish army were deployed with NATO troops in Mazar-el-Sharif, where the plains of Central Asia meet the mountains of the Hindu Kush. This deployment has now ended, and instead Sweden has entered into a new and challenging operation with the UN to the legendary city of Timbuktu, where the dry Sahel region meets the sands of the Sahara.

The implications for the European Union are obvious enough. The EU’s efforts to build a truly common foreign and security policy must rise to the top of the policy agenda, for only by acting together in the European Union, often in close partnership with the United States, can we master these challenges. Unfortunately, success isn’t even certain if we do – but failure will be inevitable if we don’t. The EU’s cohesion is a precondition for peace and stability in Europe.

Recent years have seen profound financial and economic challenges, but, until 2014, foreign affairs figured rarely on the European Council’s agenda. Daunting economic challenges remain, yet in my view the coming years will be dominated to an even greater degree by political challenges.

Revisionism in the east and disorder to the south are the most obvious, but we must also deal with the risk of the EU’s fragmentation as politicians in the United Kingdom play with the dangerous idea of leaving. A weakened and fractured union would increase the external dangers to all of us. In the 21st century, we must prepare for a rough ride.