The threat of World War Three is looming large in the public consciousness.
Last week, Defence Secretary Grant Shapps warned the world could be engulfed by wars involving China, Russia, North Korea and Iran in the next five years, and said we are moving "from a post-war to pre-war world".
The head of the British Army said UK citizens should be "trained and equipped" to fight in a potential war with Russia, describing those living today as the "pre-war generation".
General Sir Patrick Sanders' comments prompted anxiety about conscription - something Britain's former top NATO commander General Sir Richard Sherriff said it was time to consider.
Sir Patrick added that the war in Ukraine was a "pressure point" and added that "we cannot afford to make the same mistake" as our predecessors who "stumbled into... ghastly wars", such as the First World War in 1914.
Sky News spoke to experts about whether World War Three is a possibility - and if we really are living in a "pre-war world".
Here's what they had to say...
'Nuclear risk should be taken seriously'
Dr David Wearing, lecturer in international relations at the University of Sussex
"In one sense the situation now is far more perilous than it was in 1914 and 1939 because the major powers all have nuclear weapons.
"The danger here is not that one side takes the pre-meditated decision to spark the apocalypse, but rather that a conflict or area of tension escalates to a certain point, one party makes a move that another party misinterprets, and then a nuclear exchange begins despite the fact that no-one was looking for one.
"The regional war in the Middle East, with its epicentre in Gaza, is unlikely to escalate into a World War. Currently it's not a flashpoint between the major world powers.
"But the dangers are real enough, both of a genocide in Gaza (as a large body of expert opinion now fears) and of a further escalation that draws in Iran, flares into the oil heartlands of the Persian Gulf, and knocks the world economy off its axis.
"The US has repeatedly warned of conflict escalation in the Middle East, and yet repeatedly acted in ways that have now made that outcome a reality (supported throughout by the UK).
"It is widely understood by now that de-escalation requires that the US pulls the plug on Israel's assault on Gaza. The futile and dangerous military action against the Houthis is a reflection of Washington's refusal to accept that reality."
'West needs to act to avoid WWIII'
Dominic Waghorn, Sky News international affairs editor
"We are probably closer than we have been since the end of the Cold War to WWIII, but don't be alarmed. There's no need to stock the basement with bullets and beans quite yet.
"Hotspots are hotter than for a long time, fault-lines increasingly tense and war seems to be proliferating. But the alarm being raised by generals and spooks is a bit of a red herring and, let's face it, they're keen to make the case for bigger budgets and bigger roles.
"The fact is that conflict with Russia is entirely avoidable if Putin can be persuaded there is no margin in continuing his madcap misadventure in Ukraine.
"Unfortunately that is currently a bigger 'if' than it needs to be.
"Ukraine is in trouble in this war and further Western aid is being held up in both Europe and America.
"What Kyiv needs is not hypothetical debates about conscription. It needs shells, a lot more of them, and more advanced weapons - and so far the West is failing to step up to the plate.
"It failed to deter Putin from meddling in Georgia in 2008, so he did so again in Crimea in 2014 and Syria in 2015. If undeterred in Ukraine, he will almost certainly try his luck against NATO member nations in the Baltic because he will assume the alliance is too spineless to stop him.
"Instead of fanciful talk about citizens' armies and national service, the West's military and political leaders might want to focus on tackling that threat head on, putting lead in NATO's pencil and persuading our allies to do the same."
'We are in a pre-war era'
Simon Diggins, military analyst
"In one sense, we are always in a 'pre-war' world, as wars can start from miscalculation, from hubris, or misunderstandings as well as deliberate design.
"However, the last months have seen some loud rumblings, and the sense that the inevitable tensions of a complex world may only be resolvable by war.
"Nothing is inevitable, but the Ukraine invasion in particular has shown that Russia sees war as an instrument of policy, as a tool to change the world order in its favour, and not simply as a means of defence.
"China likewise seeks reunification with Taiwan, and Iran, in its region, wants its 'place in the sun'.
"What this means, in short, is that the presumption against the use of force - which was the basis for the post-WWII world order, for anything other than defence - has been lost.
"Who started this, is, of course, moot. While we can point the finger at Russia as a destabiliser, the Russians point to both the 2003 Iraq invasion - as an illegitimate use of force - and also what they regard as the "structural violence" of the eastern expansion of NATO to Russia's borders.
"The West sees that expansion as a natural and reasonable choice by individual nations. The Russians, who have long regarded themselves as a surrounded people, believe they need a bulwark of friendly, or at least, compliant countries to protect 'Mother Russia'.
"It is this disconnect of world view, combined with the willingness to use force, that makes the situation in eastern Europe so very dangerous.
"The last element is more immediate. Russia has, in the last year, doubled its defence expenditure: it now spends 6% of its GDP, or one third of all government expenditure, on the military. By contrast, we spend just over 2% of GDP or some 4.5% of government expenditure.
"Much of this is required to fight the war in Ukraine, but the Russians, ever adaptive, are using the crucible of war to reform, restructure and re-arm their forces.
"There will be a ceasefire, or some kind of uneasy stalemate - possibly this year, almost definitely by next year in Ukraine.
"We will then be faced with a 'New Russian Army', to be used where President Putin wills - and he has a long list of 're-adjustments' to correct what he sees as the disaster of the collapse of the Soviet Union.
"We are, most definitively, in a pre-war era."