As Russian, Chinese and Iranian planes arrive in Venezuela to prop up President Nicolás Maduro, key Trump administration officials signaled that the US military is ready to respond.

‘President Trump is determined not to see Venezuela fall under the sway of foreign powers,’ Trump’s national security adviser John Bolton told radio host Hugh Hewitt Wednesday. Bolton favorably referenced the Monroe Doctrine and said that if it ‘fails, if China and Russia, along with Cuba, establish domination over Venezuela, I think American strategic interests will be harmed.’

Four-star Admiral Craig Faller, who leads the US Southern Command, said the military is ‘on the balls of our feet’ awaiting instruction from the Trump administration on military intervention in Venezuela.

While he declined to give specifics on exactly what US plans in the region look like, he compared the situation to the chaos in Syria under Bashar al-Assad.

‘The crisis in Venezuela could approach that degree by the end of this year if Maduro still remains in power. It’s that bad,’ said Faller in an interview with Foreign Policy.

The US military intervened in Syria on behalf of the opposition to the brutal Assad regime. An estimated 400,000 Syrians were killed in the first five years of the country’s ongoing civil war.

As in Syria, Russia backs the authoritarian leader that the US opposes. In crisis-roiled Venezuela, the US supports Juan Guaidó’s claims that President Maduro is illegitimate, while Maduro is backed by China, Russia and Cuba.

Vice President Mike Pence summarized the administration’s position at the end of February. ‘In the wake of the brutality this weekend, where literally the dictator Maduro was dancing in Caracas at the same time that his henchmen were burning truckloads of food and medicine, I believe has only steeled the resolve of the nations across this hemisphere and around the world to stand strong in our conviction that Nicolás Maduro is a usurper, he has no legitimate claim to power, and Nicolás Maduro must go,’ he said.

Pence’s statement came before two Russian military aircraft were spotted carrying General Vasily Tonkoshkurov along with over 100 Russian troops landed in Caracas last month. Last week, it was reported that the Chinese army sent an additional 120 troops, though a spokesman for China’s Foreign Ministry claimed the report is inaccurate. US Southern Command declined to comment, though they have said that China sold over $615 million in weapons to Venezuela in the past decade.

Faller, who was previously director of operations at US Central Command, said the US military is ‘looking at a range’ of options and ‘will be ready’ to implement whatever President Trump decides to do in Venezuela.

‘China is hedging its bets and being unhelpful’ in Venezuela, Faller told Foreign Policy. ‘For a nation who wishes to stake their claim amongst the great nations, they are certainly not respecting human rights, sovereignty, democracy — any of the things that this neighborhood values.’

China has offered to help the Venezuelan government restore its power grid after Maduro blamed the US for blackouts.

China’s investment in infrastructure and loans to Venezuela leverages the country economically to Beijing, and gives China access to the country’s vast oil exports. This has been going on for over a decade; by 2014, they had financed over $30 billion loans-for-oil to Caracas. Those loans have provided artificial life support to the country’s corrupt regime.

‘I think the biggest threat to democracy and the way of life around the world is the trend that we see in China,’ Faller said.

‘We are seeing here the palpable proof of eight years of Obama administration policy mistakes,’ said Bolton.

In a sign of the escalated rhetoric, Vice President Mike Pence appealed directly to envoy Samuel Moncada at a Wednesday meeting of the UN Security Council meeting, ‘With all due respect, Mr Ambassador, you shouldn’t be here, you should return to Venezuela and tell Nicolás Maduro that his time is up, it’s time for him to go.’