Large-scale deployments look to be off the US military’s agenda in an era of budget cuts and post-Iraq and Afghanistan retrenchment. But smaller missions that can produce big effects on the ground are still viable.

The Pentagon’s decision to dispatch 200 Marines to Guatemala is one such attempt to do more with less. The objective of “Operation Hammer” is to wage war on the Zeta drug cartel, a Mexico-based crime organisation whose influence is spreading south through Central America, even as their drugs spread north through the US. A number of other countries are also taking part.

The Marines are now patrolling the Guatemalan coast and inland waterways looking for the traffickers and the tools of their trade: “narco-subs”, mini-submarines used to smuggle drugs across borders, and “go-fasts”, high-powered speedboats that fulfil the same role.

The advantage of a lean mission is that the risks, in terms of American lives and resources, are relatively low. However, expectations must be reined in. “The nations involved in counterdrug efforts in Central America spend, as a whole, less than $150m [€116m] a year on those efforts,” says Ralph Espach, director of the Latin American Affairs Program at cna, a US think-tank. “The narcotics industry grosses between $15bn [€11.6bn] and $40bn [€31bn] a year in the Americas. So the traffickers have plenty of resources and options.”

1. Central African Republic: 200 special forces are helping 5,000 African Union troops in the hunt for guerrilla leader Joseph Kony.
2. Philippines: 600 US Marines are helping the Philippine military to target Islamist militants.
3. Honduras: 350 American troops are attempting to disrupt Honduran drug runners.

The US military is facing its worst threat in years: not Iran, or China, but political gridlock in Washington. The gun being pointed at US forces is “sequestration”: a system of severe budget cuts that automatically kicks in unless Congress passes a budget, which bickering Democrats and Republicans have failed to do this year. Sequestration would mean an 11 per cent budget reduction on top of the cuts already announced by the Pentagon (below). That would devastate a number of key procurement programmes and could endanger the US’s status as the world’s top military power. The axe falls on 3 January unless Congress gets to work.

From ligatures to the discovery of penicillin, combat has led to important medical advances. The use of landmines and improvised explosive devices (IEDs) in Afghanistan and Iraq is now driving innovation in reconstructive surgery and infection control.

Austria is holding a referendum in January on whether to scrap conscription. Currently, male citizens have to serve in the military for six months before entering the reserves or spend nine months doing civic duty. The government is backing reform, arguing that a fully professional army would be better equipped to deal with modern challenges. However, many Austrians like the old system. Conscripts come cheap and national service also benefits society, according to the “no” campaign.

The Chinese navy’s first aircraft carrier (below) is weeks away from entering active service. However, this showy piece of hardware may not be the most effective capability that China’s naval commanders are bringing online. That might be the new Type 059D destroyer, the first of which was launched in August. Nine more are thought to be under construction. They are designed to match the advanced destroyers already operated in the region by Japan, South Korea and the US. These use radar and missile interceptors to provide a defensive shield for themselves and other ships in the fleet. The Type 059Ds will make Chinese ships much harder targets for foreign navies.