Here’s a look at 4 internal trouble spots threatening the EU’s unity

LISBON, Portugal — There's little doubt that Europe sorely needs a dose of strength and unity right now.

The Islamic State (IS) has spread from its bases in Syria and Iraq along the southern shores of the Mediterranean, slaughtering Christians on a Libyan beach and issuing bloodcurdling threats to export devastation to southern Europe.

To the east, Russian leader Vladimir Putin is pushing ahead with the dismemberment of Ukraine despite the ceasefire cobbled together by France and Germany. 

Yet, beset by internal problems, Europe is struggling to muster a coherent response.

After IS threatened to conquer Rome last week on a beach barely 500 miles from Sicily, Defense Minister Roberta Pinotti suggested Italy could lead an international coalition against the "imminent" threat of militants across the sea.

Italy soon backtracked. "It's not the time for a military intervention," said Prime Minister Matteo Renzi. Instead, he said Rome would deploy "wisdom, prudence and a sense of situation" to tackle the threat in Libya.

The conquest of the Ukrainian town of Debaltseve by pro-Putin forces days after the ceasefire mentored by French President Francois Hollande and German Chancellor Angela Merkel was greeted in Europe by a barrage of statements expressing concern of the type the Kremlin has repeatedly ignored over the past year.

With Ukraine now bracing for an attack on the key Black Sea port of Mariupol, European Union leaders are mulling more sanctions.

However, their only concrete measure in recent weeks has been the addition of a handful of Russian officials to an EU travel ban and asset freeze — the highest-profile target is a nationalist crooner-turned-lawmaker once dubbed the Soviet Sinatra.

Underlying Europe's lack of resolve are a series of economic and political fault lines which have fractured the internal cohesion of the EU and NATO. Here's a look at four of them:

1. Greece

Today's last-gasp deal between Greece's new government and its partners in the euro zone has given the country a four-month extension on its bailout. But risks that the debt-ridden country could be forced out of the currency bloc, with potentially catastrophic consequences, have not gone away.

Fundamental differences remain between the demands by Germany and other euro zone nations — that Greece stick to fiscal discipline and reforms to boost competitiveness in return for loans essential for keeping the economy afloat — and the election pledges of far-left Prime Minister Alexis Tsipras. He's promised to break free from restraints imposed by Greece's creditors and reverse austerity policies he blames for shrinking the economy and spreading hardship.

Markets, for the moment, seem to have faith in EU firewalls designed to prevent a "Grexit" from infecting other fragile euro zone countries, such as Portugal, Spain and Ireland. But there’s still a risk of contagion.

Even if Greece goes alone, the impact would be enormous. Athens would likely default on the $360 billion it owes; the economy would hemorrhage cash; the banking system could collapse.

Then there are the geopolitics.

Tsipras' Greek government has made no secret of its desire for friendly relations with Moscow. Russia has reciprocated by offering to step in should EU financing run out.

If Greece were forced out of the euro zone and EU, many are questioning the impact on its commitment to NATO, where it has long held a strategic position on the alliance's southeastern flank.

2. Hungary

Another of Putin's friends in Europe is Hungarian Prime Minister Viktor Orban.

As troops loyal to the Russian leader closed the noose on Debaltseve, Ukraine last week, Orban was rolling out the red carpet for Putin in Budapest.

Amid the mutual backslapping, Putin came making cheap gas offers that Orban found impossible to refuse — despite EU efforts to reduce the 28-nation bloc's dependency on Russian fuel imports.

Having secured a long-term gas supply deal with Putin, Orban said he expected an "escalating conflict" to bloc EU efforts to unify its energy market, then announced Hungary would refrain from re-sales of Russian gas to Ukraine.

“Those who think that the European economy can be competitive without Russian economic cooperation, that energy security can be achieved in Europe without Russian energy, are chasing illusions,” he told reporters.

The Budapest trip was Putin's first bilateral invite from an EU leader for months, as other European governments give him the cold shoulder. But the Kremlin is stepping up its outreach, seeking meetings in coming weeks with leaders of other friendly EU countries — like Greece and Cyprus — in an apparent attempt to undermine the bloc's efforts to forge a united response.

Orban — who has been criticized by other EU leaders for squeezing Hungary's judiciary, press and civil society — made a speech last year outlining his objective to create an "illiberal new state." He cited Putin's Russia as a role model.

3. Britain

Britain's role in Europe is a key issue ahead of general elections set for May. In early campaigning, much of the running is being made by the upstart United Kingdom Independence Party, which wants to pull Britain out of the EU.

Polls show UKIP — whose leader Nigel Farage names Putin as the foreign politician he most admires — finishing in third place with around 15 percent. That's five times more than it got in the last vote in 2010.

UKIP won't win, and its score of seats will be limited by Britain's electoral system, which favors established parties. But it's influence on the race is huge.

Fearful of the euro-skeptics' undermining of his core Conservative support, Prime Minister David Cameron has vowed to call a referendum on pulling Britain out of the EU if he's re-elected.

Public opinion is split down the middle, but the debate on a "Brexit" and Cameron's pledge to weaken the EU's role is affecting British influence in Europe.

Officials at EU headquarters in Brussels complain Britain, which rivals France as Western Europe's biggest military power, no longer pulls its diplomatic weight in Europe.

Cameron has been largely sidelined in EU efforts to resolve Ukraine's crisis. Instead Merkel and Hollande have taken the lead — to the discomfort of those who see them as too willing to appease Putin.

At NATO too, Britain's traditional role as the United States' staunchest European ally is no longer taken for granted.

US commanders are worried British defense spending may soon slip below NATO's 2 percent of GDP target — a development that would leave Greece and Estonia as the only European allies above the alliance's threshold.

Britain's fading will to fight alongside the US was highlighted in 2013 when lawmakers voted down Cameron's proposal for the Royal Air Force to join airstrikes in Syria.

Although Britain now participates in the US-led air campaign against IS in Iraq, its contribution is "strikingly modest" according to a report this month from the House of Commons’ Defense Select Committee. Legislators said they were "surprised and deeply concerned" British forces were not playing a greater role.

4. France

Amid the frenzied efforts during the past month to head off an existential crisis over Greece, the euro zone's broader economic blight has dropped from the headlines.

Yet, even without the risk of Grexit, prospects for many in the 19-nation currency bloc were looking grim.

After years without economic growth, falling prices prompted fears the bloc will be sucked into a deflationary spiral dragging down investment, raises debt and cementing stagnation.

In response, the European Central Bank on Jan. 22 agreed to pump around $1.25 trillion into the economy over the next year and a half. Many economists fear even that will not solve the problem unless governments push through reforms to make their economies more competitive.

France and Italy are key. Italy's economy has shrunk by 4.7 percent over the past three years. France has stood still.

Both governments are touting reform, but Hollande in particular faces stiff resistance. A rebellion by lawmakers in his Socialist Party last week threatened to block a modest package of pro-business measures — like allowing stores to stay open more on Sundays and letting private buses compete against inter-city trains.

In a rare move, the government pushed through the reforms by decree circumventing parliament, but that has done nothing to bolster Hollande's approval ratings which dropped to just 24 percent, according to a poll published Sunday, reversing the brief jump in support following last month's Paris terror attacks.

Europe's weakened economy makes it harder for the EU to wean itself off cheap Russian gas, or muster support for sanctions that hurt trade.

Putin could also benefit from Hollande's political woes.

Former President Nicolas Sarkozy, who leads the mainstream opposition, has made comments recently that appear to legitimize Russia's annexation of Crimea, dismiss Ukraine's EU membership ambitions, and suggest the US stirred up antagonism against Russia.

And the far-right National Front — France's most popular party according to a poll published Monday — gets funding from Russian banks and is assertively pro-Putin.

More from GlobalPost: Greece and Ukraine have something in common: They could both sink the euro zone