(Bloomberg) — US equities investors are reluctant to seek safety amid flaring geopolitical tensions, raising the risk of getting caught off guard if the conflict between Israel and Iran takes an unexpected turn in the days ahead.

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Normally, this level of anxiety would be enough to send money managers scurrying into stocks offering shelter, especially with President Donald Trump weighing whether to offer Israel military backing in its conflict with Iran. That step could roil crude prices and stoke worries about inflation, and potentially reignite a rush for investment havens.

Yet, the events since last week have only triggered a modest shift into so-called defensive sectors such as utilities, consumer staples and health care. That’s even as US stocks whipsaw their way higher, with the S&P 500 Index (^GSPC) is just 2.7% away from a new all-time high.

For Matt Maley at Miller Tabak + Co., it’s an ominous setup that leaves investors vulnerable given the fluid situation.

“The war may or may not get worse, but given that any upside potential for stocks is limited due to extended valuations, investors should be taking more precautions,” said the firm’s chief market strategist.

Underscoring how safer stocks have been on the sidelines lately, defensive sectors’ influence on the benchmark — measured by the combined weight of the groups in the gauge — is currently at a 35-year low, Strategas’ Todd Sohn found.

What’s more, a Goldman Sachs Group Inc. (GS) pair-trade basket that represents going long cyclicals and short defensives has seen a modest uptick since Israel launched airstrikes against Iran’s nuclear program and military targets last week. If traders were rushing to safety due to concerns over the economy the basket would decline, like it did in early April, when investors feared the impact of tariffs on growth. Trump will decide within two weeks whether to strike Iran, his spokeswoman said on Thursday.

Some say there’s good reason for investors to be reluctant to jump into defensives in the face of geopolitical unrest. First, data from UBS shows the impact of such events on equity markets tend to be short-lived. In the past 11 major geopolitical events, the S&P 500 on average fell just 0.3% one week after the event, while 12 months later it rose 7.7%.