Due to the escalation in eastern Ukraine, the U.S. considers tougher sanctions against Russia. Above all, however, President Obama wants to be cautious.

Ukrainians call them the “little green men.” In Eastern Ukraine, they stand in the leadership and the advance guard, just as in March in Crimea. They do not come from Mars, but from Russia. They are dressed and armed just like Russian Spetsnaz (special forces). As during the capture of Crimea, all they are missing are insignia and reddish-brown berets.

The unwelcome guests are now at work in eastern Ukraine. Over the weekend, The Wall Street Journal reported from Kiev that they began to organize local followers (the newspaper speaks of “thugs”). For a bounty equivalent to $40 to $500, it states that the latter have attacked police stations and government buildings. However, in contrast to Crimea where the Ukrainian government sat helpless as protests spread, Kiev wants to fight this time. The first shots were fired on Tuesday as soldiers dispersed an armed mob from a Ukrainian base. To quote the incumbent President Oleksandr Turchynov: “We will not allow Russia to repeat the Crimean scenario.” He speaks carefully of a “phased, responsible and balanced” operation.

The second difference: The Obama administration, which has thus far only reacted with symbolic sanctions like travel bans for Moscow officials, is showing some sharper teeth — or it wants to. Fundamentally, Obama continues to keep to the old course. He wants neither to push Russia toward escalation nor to encourage Ukrainians to expand the conflict.

In the meantime, however, Washington appears so suspect of Russian assurances that it plans no direct intervention. The talk in Washington is now of a “menu” of responses which includes:

• More severe economic sanctions, which would have to be backed by the Europeans;

• The deployment of a “small” contingent of American troops to the eastern NATO member states;

• The mobilization of larger forces in the event that Moscow openly intervenes. Of course, these forces — of about brigade-size — would not be moved directly forward to the Russian border, but rather, for example, to Romania.

Above all, caution reigns. Military movements must be approved by the NATO alliance, which — given the maneuvering of EU capitals — is not guaranteed by any means. The main function of such troop deployments, it’s said in Washington, is to bolster the confidence of eastern NATO members, not to scare the Russians. America will also not outfit Ukraine with “lethal” military support. To date, it has only provided field rations.

For the moment, the U.S. does nothing at all. Anticipation turns to today (Thursday, April 17), when Secretary of State Kerry’s talks with his Russian, Ukrainian and EU counterparts begin. These will be flanked by Vice President Biden's trips to Kiev, which should signal from the very top: "We stand on Ukraine’s side."

The bottom line: Exhibit resolve, but do not take risks. This is a test of wills, not yet of strength. So far, Putin has it easier. He lets his “little green men” — highly efficient special forces without insignia — do the work, and he can rely on pro-Russian forces in eastern Ukraine while calmly stating, “We do not yet intervene.”

Back to the Europeans and the classic Obama motto, "Lead from behind.” In The Wall Street Journal, an unnamed senior administration official hopes that the EU will come around to tougher sanctions: “They get the message that if the Russians either invade or keep escalating this current effort, a bigger hammer has to drop.” Of course, the Americans do not exactly want to describe the hammer, much less swing it themselves anytime soon.

America is far away, and Russia is very close. Putin has the greater leverage.