Small US companies, the source of more than half of the country’s job creation in recent years, are struggling to comply with President Donald Trump’s new tariffs and cope with growing financial strains clobbering them from higher import costs. Last week’s country-specific levies varying from 10% to 50% landed with a one-two punch: additional red tape issued by Customs and Border Protection, and a need to increase customs bonds — guarantees that companies must buy from surety providers to ensure the government receives its tariff revenue, other taxes and any potential penalties.