Russia’s navy conducts live-fire exercises. Greek and Turkish ships collide while staking claims to undersea resources. Civil war rages in Libya and smolders in Syria, drawing in outside powers with competing agendas and little love for one another. European coast guards and navies struggle to stem a flood of refugees fleeing unrest in North Africa and the Levant. And on and on. While military and maritime folk rightly focus on managing events in maritime Asia, the headlines serve notice that the Mediterranean Sea is far from placid. Newsworthy events are commonplace of late.

If the tyranny of distance makes it hard to operate along the far shores of the Pacific theater, the Mediterranean Sea suffers from the tyranny of proximity. The closer competitors are, the tougher it is to coexist in harmony.

Now more than ever, the middle sea makes an extraordinarily difficult combat theater. Start with geography. To forecast how interactions may unfold, it’s natural to begin by surveying the arena where contenders strive with one another. The Mediterranean ranges about 2,300 miles along its east-west axis from the Strait of Gibraltar to the Lebanese seaport of Beirut. That sounds gigantic. After all, only about 3,800 miles separate the U.S. Navy hub at Norfolk, Virginia, from Gibraltar. And that’s across the vacant vastness of one of the planet’s great oceans, the Atlantic.

But raw east-west distance deceives. If the middle sea—in effect an inlet in the supercontinent formed by Europe and Africa—is broad horizontally, it is slim vertically. Only about 450 miles separate the French harbor at Marseilles from the Algerian seacoast, marking the widest point (measured north to south) in the Mediterranean’s western reaches. To the east the heel of the Italian boot lies just 650 miles or so from the deepest recesses of Libya’s Gulf of Sidra.

That’s as tall as the Mediterranean gets. Unlike other enclosed or semi-enclosed “marginal seas” like the South China Sea or Caribbean Sea, the Mediterranean resembles a strip of water meandering from east to west more than an open body of water. It also has solid borders, unlike, say, the Caribbean, whose Lesser Antilles—the island chain constituting the sea’s permeable easternmost frontier—barely obstruct passage between America’s middle sea and the Atlantic. The Caribbean is an open system by contrast with the Mediterranean, which is tantamount to a closed system.

After all, shipping can enter or exit the Mediterranean Sea via just three portals. Two of them—the Suez Canal and the Bosporus and Dardanelles—can be shut with relative ease in times of sea war. Turn up the heat in a closed vessel and the pressure escalates along with the temperature. That physics metaphor is one way to interpret tidings of warlike doings in the middle sea.

Nor is navigation a straightforward matter even within the Mediterranean. The Italian peninsula and Sicily in effect subdivide the sea into eastern and western halves, leaving a corridor just 100 miles wide separating Sicily from North Africa. The narrows is not open sea. It’s slenderer than the Miyako Strait—a passageway through Japan’s Ryukyus chain that vexes China’s navy—by about 50 miles. Blessed or cursed by its central position overlooking the narrow sea, Sicily has been prized real estate for ambitious powers for centuries.

Small wonder the Athenian adventurer Alcibiades wanted to occupy the island and use it as a springboard to conquer North Africa, Italy, and western Greece. And small wonder Allied armies commanded by George S. Patton and Bernard Montgomery vaulted across the narrows from North Africa to assault Sicily before using the island as a platform to leap into southern Italy around this time in 1943. Land—not just continental shorelines but strategically placed islands—overshadows regional waterways.

Next, military strategy. Little if any of the middle sea qualifies as a safe haven for shipping in this age of long-range precision armaments. To pick a couple of examples at random, U.S. Air Force bombers and U.S. Navy carrier warplanes now sport long-range anti-ship missiles (LRASMs) with a range advertised at 200 miles. (That doubtless understates the true figure, as publicly released Pentagon figures are wont to do.) Couple that with the very long range of an Air Force bomber or even the modest range of a Navy fighter and it appears LRASM-armed jets can now strike at ships anywhere in the Mediterranean basin.

Nor is sea power of extreme reach purely an American thing. The Soviet Air Force long equipped and trained to reach out and smite U.S. Navy task forces cruising along Eastern Bloc coasts. Five years ago Russian Navy warships sent cruise missiles crashing into ISIS targets in Syria from the remote Caspian Sea, over 900 miles distant. These were land-attack missiles, to be sure, but land-attack missiles can be repurposed with seekers for assailing shipping—as the U.S. military has commenced doing with its venerable Tomahawks.

Navies and merchant fleets thus operate under the shadow of air or missile attack, either from sea or from land, throughout the Mediterranean. Lord Nelson reputedly joked that a ship’s a fool to fight a fort, but the sail-driven ships of his day could bypass forts for the most part. No more in the age of Fortress Europe and Africa.

And lastly, politics. Societies of many shapes and sizes crowd the banks of the Mediterranean. No natural hegemon enjoys dominion over states ringing the middle sea the way the United States bestrides the Caribbean Sea and Gulf of Mexico or China dominates the South China Sea. Many are middle powers allied to one another and the United States through NATO. A couple are formerly middling powers now riven by civil war, in particular Syria and Libya. And external great powers such as America, Russia, and to a lesser extent China take a keen interest in Mediterranean affairs.

While geography is fixed, more or less, geopolitics doyen Nicholas Spykman once pointed out that geopolitical theaters are shapeshifters. A geopolitical region is far more than its physical features. It encompasses the human dimension. Its geopolitical terrain metamorphoses over time as contenders come and go, rise and fall, and perhaps rise again. For example, Russian influence went into recession after the Soviet Union fell, while the United States reduced its military presence in Europe to harvest a peace dividend and, later on, to free up forces to wage war in Iraq and Afghanistan.

Among the outsiders, Russia is attempting a comeback while U.S. leaders mull to what extent they should station new forces in the region as a counterweight. Among Europeans, France and Great Britain are set on remaining powers of the first rank, for instance by continuing to operate aircraft carriers and sending them to offset Chinese power in Asia. In the Levant, Israel now deploys F-35 stealth fighters and an impressive—and probably nuclear-armed—submarine fleet. And so forth. Tallying up indices of national purpose and power helps observers glimpse the Mediterranean’s shifting geopolitical terrain, along with potential futures and strategic options for managing them.

With changing power and purpose comes the likelihood of geopolitical transients and the turbulence that accompanies them. As daily headlines indicate, some contenders are at odds with one another in this cramped theater. They jostle for geopolitical advantage or natural resources, sometimes in quarrels of long standing. Disputes often overlap or commingle, making them wickedly intricate and hard to manage absent fellow-feeling among nations—amity that has been in short supply of late. In short, geopolitical disputes come in layers, in the Mediterranean world as in other contested expanses around the Eurasian perimeter.

Here are three.

First of all, coastal states are jealous of their sovereignty and rights to offshore natural resources. In the Mediterranean as elsewhere, notably in the South China Sea, nonmilitary shipping—coast-guard cutters, vessels from nonmilitary maritime agencies, even merchantmen—is the implement of choice for governments defending what they regard as waters allotted to them by international law. Navies are a backstop. In recent weeks, for instance, the Turkish survey ship Oruc Reis explored for resources in waters also claimed by Greece. Greek and Turkish warships collided while trailing Oruc Reis—showing how purportedly civilian endeavors could cascade into military conflict.

Thankfully, Ankara has recalled its survey vessel from the disputed zone, and it appears the Turkish and Greek capitals will convene talks aimed at demarcating maritime territory between them. Even so, a Turkish drilling ship and seismic survey ship continue plying waters claimed by Cyprus—eliciting an outcry from Cypriot officials. The Oruc Reis affair was an eccentric one, fanning the prospect of geopolitical competition or even warfare within the NATO alliance, history’s most successful and enduring martial fellowship. It seems “gray-zone” strategies are not for China alone.

Complex, congested terrain makes it nigh on impossible to sketch lines on the map indicating what belongs to whom, and that everyone regards as just. May goodwill prevail in Athens and Ankara as it has not in Beijing.

Second, internal strife wracks certain Mediterranean states, notably Libya and Syria. In 2011 NATO overthrew Libyan strongman Moammar Ghadafi in a fit of absentmindedness, plunging the country into civil war. Rival factions took up the sword to determine who would rule. Syria fell into chaos when protests against the Baathist regime of Bashar al-Assad escalated into fighting between government and anti-government forces, Syrian Kurds and Turkish forces, and outsiders battling ISIS, which had exploited the power vacuum to entrench itself in Syrian-Iraqi borderlands. The conflict embroiled external powers such as Russia, Iran, and the United States as well as Turkey.